/*  Prototype JavaScript framework, version 1.5.1
 *  (c) 2005-2007 Sam Stephenson
 *
 *  Prototype is freely distributable under the terms of an MIT-style license.
 *  For details, see the Prototype web site: http://www.prototypejs.org/

Permission is hereby granted, free of charge, to any person obtaining a 
copy of this software and associated documentation files (the "Software"), to 
deal in the Software without restriction, including without limitation the 
rights to use, copy, modify, merge, publish, distribute, sublicense, and/or 
sell copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 
OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 
THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS 
IN THE SOFTWARE.
 *
/*--------------------------------------------------------------------------*/

var Prototype = {
  Version: '1.5.1',

  Browser: {
    IE:     !!(window.attachEvent && !window.opera),
    Opera:  !!window.opera,
    WebKit: navigator.userAgent.indexOf('AppleWebKit/') > -1,
    Gecko:  navigator.userAgent.indexOf('Gecko') > -1 && navigator.userAgent.indexOf('KHTML') == -1
  },

  BrowserFeatures: {
    XPath: !!document.evaluate,
    ElementExtensions: !!window.HTMLElement,
    SpecificElementExtensions:
      (document.createElement('div').__proto__ !==
       document.createElement('form').__proto__)
  },

  ScriptFragment: '<script[^>]*>([\u0001-\uFFFF]*?)</script>',
  JSONFilter: /^\/\*-secure-\s*(.*)\s*\*\/\s*$/,

  emptyFunction: function() { },
  K: function(x) { return x }
}

var Class = {
  create: function() {
    return function() {
      this.initialize.apply(this, arguments);
    }
  }
}

var Abstract = new Object();

Object.extend = function(destination, source) {
  for (var property in source) {
    destination[property] = source[property];
  }
  return destination;
}

Object.extend(Object, {
  inspect: function(object) {
    try {
      if (object === undefined) return 'undefined';
      if (object === null) return 'null';
      return object.inspect ? object.inspect() : object.toString();
    } catch (e) {
      if (e instanceof RangeError) return '...';
      throw e;
    }
  },

  toJSON: function(object) {
    var type = typeof object;
    switch(type) {
      case 'undefined':
      case 'function':
      case 'unknown': return;
      case 'boolean': return object.toString();
    }
    if (object === null) return 'null';
    if (object.toJSON) return object.toJSON();
    if (object.ownerDocument === document) return;
    var results = [];
    for (var property in object) {
      var value = Object.toJSON(object[property]);
      if (value !== undefined)
        results.push(property.toJSON() + ': ' + value);
    }
    return '{' + results.join(', ') + '}';
  },

  keys: function(object) {
    var keys = [];
    for (var property in object)
      keys.push(property);
    return keys;
  },

  values: function(object) {
    var values = [];
    for (var property in object)
      values.push(object[property]);
    return values;
  },

  clone: function(object) {
    return Object.extend({}, object);
  }
});

Function.prototype.bind = function() {
  var __method = this, args = $A(arguments), object = args.shift();
  return function() {
    return __method.apply(object, args.concat($A(arguments)));
  }
}

Function.prototype.bindAsEventListener = function(object) {
  var __method = this, args = $A(arguments), object = args.shift();
  return function(event) {
    return __method.apply(object, [event || window.event].concat(args));
  }
}

Object.extend(Number.prototype, {
  toColorPart: function() {
    return this.toPaddedString(2, 16);
  },

  succ: function() {
    return this + 1;
  },

  times: function(iterator) {
    $R(0, this, true).each(iterator);
    return this;
  },

  toPaddedString: function(length, radix) {
    var string = this.toString(radix || 10);
    return '0'.times(length - string.length) + string;
  },

  toJSON: function() {
    return isFinite(this) ? this.toString() : 'null';
  }
});

Date.prototype.toJSON = function() {
  return '"' + this.getFullYear() + '-' +
    (this.getMonth() + 1).toPaddedString(2) + '-' +
    this.getDate().toPaddedString(2) + 'T' +
    this.getHours().toPaddedString(2) + ':' +
    this.getMinutes().toPaddedString(2) + ':' +
    this.getSeconds().toPaddedString(2) + '"';
};

var Try = {
  these: function() {
    var returnValue;

    for (var i = 0, length = arguments.length; i < length; i++) {
      var lambda = arguments[i];
      try {
        returnValue = lambda();
        break;
      } catch (e) {}
    }

    return returnValue;
  }
}

/*--------------------------------------------------------------------------*/

var PeriodicalExecuter = Class.create();
PeriodicalExecuter.prototype = {
  initialize: function(callback, frequency) {
    this.callback = callback;
    this.frequency = frequency;
    this.currentlyExecuting = false;

    this.registerCallback();
  },

  registerCallback: function() {
    this.timer = setInterval(this.onTimerEvent.bind(this), this.frequency * 1000);
  },

  stop: function() {
    if (!this.timer) return;
    clearInterval(this.timer);
    this.timer = null;
  },

  onTimerEvent: function() {
    if (!this.currentlyExecuting) {
      try {
        this.currentlyExecuting = true;
        this.callback(this);
      } finally {
        this.currentlyExecuting = false;
      }
    }
  }
}
Object.extend(String, {
  interpret: function(value) {
    return value == null ? '' : String(value);
  },
  specialChar: {
    '\b': '\\b',
    '\t': '\\t',
    '\n': '\\n',
    '\f': '\\f',
    '\r': '\\r',
    '\\': '\\\\'
  }
});

Object.extend(String.prototype, {
  gsub: function(pattern, replacement) {
    var result = '', source = this, match;
    replacement = arguments.callee.prepareReplacement(replacement);

    while (source.length > 0) {
      if (match = source.match(pattern)) {
        result += source.slice(0, match.index);
        result += String.interpret(replacement(match));
        source  = source.slice(match.index + match[0].length);
      } else {
        result += source, source = '';
      }
    }
    return result;
  },

  sub: function(pattern, replacement, count) {
    replacement = this.gsub.prepareReplacement(replacement);
    count = count === undefined ? 1 : count;

    return this.gsub(pattern, function(match) {
      if (--count < 0) return match[0];
      return replacement(match);
    });
  },

  scan: function(pattern, iterator) {
    this.gsub(pattern, iterator);
    return this;
  },

  truncate: function(length, truncation) {
    length = length || 30;
    truncation = truncation === undefined ? '...' : truncation;
    return this.length > length ?
      this.slice(0, length - truncation.length) + truncation : this;
  },

  strip: function() {
    return this.replace(/^\s+/, '').replace(/\s+$/, '');
  },

  stripTags: function() {
    return this.replace(/<\/?[^>]+>/gi, '');
  },

  stripScripts: function() {
    return this.replace(new RegExp(Prototype.ScriptFragment, 'img'), '');
  },

  extractScripts: function() {
    var matchAll = new RegExp(Prototype.ScriptFragment, 'img');
    var matchOne = new RegExp(Prototype.ScriptFragment, 'im');
    return (this.match(matchAll) || []).map(function(scriptTag) {
      return (scriptTag.match(matchOne) || ['', ''])[1];
    });
  },

  evalScripts: function() {
    return this.extractScripts().map(function(script) { return eval(script) });
  },

  escapeHTML: function() {
    var self = arguments.callee;
    self.text.data = this;
    return self.div.innerHTML;
  },

  unescapeHTML: function() {
    var div = document.createElement('div');
    div.innerHTML = this.stripTags();
    return div.childNodes[0] ? (div.childNodes.length > 1 ?
      $A(div.childNodes).inject('', function(memo, node) { return memo+node.nodeValue }) :
      div.childNodes[0].nodeValue) : '';
  },

  toQueryParams: function(separator) {
    var match = this.strip().match(/([^?#]*)(#.*)?$/);
    if (!match) return {};

    return match[1].split(separator || '&').inject({}, function(hash, pair) {
      if ((pair = pair.split('='))[0]) {
        var key = decodeURIComponent(pair.shift());
        var value = pair.length > 1 ? pair.join('=') : pair[0];
        if (value != undefined) value = decodeURIComponent(value);

        if (key in hash) {
          if (hash[key].constructor != Array) hash[key] = [hash[key]];
          hash[key].push(value);
        }
        else hash[key] = value;
      }
      return hash;
    });
  },

  toArray: function() {
    return this.split('');
  },

  succ: function() {
    return this.slice(0, this.length - 1) +
      String.fromCharCode(this.charCodeAt(this.length - 1) + 1);
  },

  times: function(count) {
    var result = '';
    for (var i = 0; i < count; i++) result += this;
    return result;
  },

  camelize: function() {
    var parts = this.split('-'), len = parts.length;
    if (len == 1) return parts[0];

    var camelized = this.charAt(0) == '-'
      ? parts[0].charAt(0).toUpperCase() + parts[0].substring(1)
      : parts[0];

    for (var i = 1; i < len; i++)
      camelized += parts[i].charAt(0).toUpperCase() + parts[i].substring(1);

    return camelized;
  },

  capitalize: function() {
    return this.charAt(0).toUpperCase() + this.substring(1).toLowerCase();
  },

  underscore: function() {
    return this.gsub(/::/, '/').gsub(/([A-Z]+)([A-Z][a-z])/,'#{1}_#{2}').gsub(/([a-z\d])([A-Z])/,'#{1}_#{2}').gsub(/-/,'_').toLowerCase();
  },

  dasherize: function() {
    return this.gsub(/_/,'-');
  },

  inspect: function(useDoubleQuotes) {
    var escapedString = this.gsub(/[\x00-\x1f\\]/, function(match) {
      var character = String.specialChar[match[0]];
      return character ? character : '\\u00' + match[0].charCodeAt().toPaddedString(2, 16);
    });
    if (useDoubleQuotes) return '"' + escapedString.replace(/"/g, '\\"') + '"';
    return "'" + escapedString.replace(/'/g, '\\\'') + "'";
  },

  toJSON: function() {
    return this.inspect(true);
  },

  unfilterJSON: function(filter) {
    return this.sub(filter || Prototype.JSONFilter, '#{1}');
  },

  evalJSON: function(sanitize) {
    var json = this.unfilterJSON();
    try {
      if (!sanitize || (/^("(\\.|[^"\\\n\r])*?"|[,:{}\[\]0-9.\-+Eaeflnr-u \n\r\t])+?$/.test(json)))
        return eval('(' + json + ')');
    } catch (e) { }
    throw new SyntaxError('Badly formed JSON string: ' + this.inspect());
  },

  include: function(pattern) {
    return this.indexOf(pattern) > -1;
  },

  startsWith: function(pattern) {
    return this.indexOf(pattern) === 0;
  },

  endsWith: function(pattern) {
    var d = this.length - pattern.length;
    return d >= 0 && this.lastIndexOf(pattern) === d;
  },

  empty: function() {
    return this == '';
  },

  blank: function() {
    return /^\s*$/.test(this);
  }
});

if (Prototype.Browser.WebKit || Prototype.Browser.IE) Object.extend(String.prototype, {
  escapeHTML: function() {
    return this.replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;');
  },
  unescapeHTML: function() {
    return this.replace(/&amp;/g,'&').replace(/&lt;/g,'<').replace(/&gt;/g,'>');
  }
});

String.prototype.gsub.prepareReplacement = function(replacement) {
  if (typeof replacement == 'function') return replacement;
  var template = new Template(replacement);
  return function(match) { return template.evaluate(match) };
}

String.prototype.parseQuery = String.prototype.toQueryParams;

Object.extend(String.prototype.escapeHTML, {
  div:  document.createElement('div'),
  text: document.createTextNode('')
});

with (String.prototype.escapeHTML) div.appendChild(text);

var Template = Class.create();
Template.Pattern = /(^|.|\r|\n)(#\{(.*?)\})/;
Template.prototype = {
  initialize: function(template, pattern) {
    this.template = template.toString();
    this.pattern  = pattern || Template.Pattern;
  },

  evaluate: function(object) {
    return this.template.gsub(this.pattern, function(match) {
      var before = match[1];
      if (before == '\\') return match[2];
      return before + String.interpret(object[match[3]]);
    });
  }
}

var $break = {}, $continue = new Error('"throw $continue" is deprecated, use "return" instead');

var Enumerable = {
  each: function(iterator) {
    var index = 0;
    try {
      this._each(function(value) {
        iterator(value, index++);
      });
    } catch (e) {
      if (e != $break) throw e;
    }
    return this;
  },

  eachSlice: function(number, iterator) {
    var index = -number, slices = [], array = this.toArray();
    while ((index += number) < array.length)
      slices.push(array.slice(index, index+number));
    return slices.map(iterator);
  },

  all: function(iterator) {
    var result = true;
    this.each(function(value, index) {
      result = result && !!(iterator || Prototype.K)(value, index);
      if (!result) throw $break;
    });
    return result;
  },

  any: function(iterator) {
    var result = false;
    this.each(function(value, index) {
      if (result = !!(iterator || Prototype.K)(value, index))
        throw $break;
    });
    return result;
  },

  collect: function(iterator) {
    var results = [];
    this.each(function(value, index) {
      results.push((iterator || Prototype.K)(value, index));
    });
    return results;
  },

  detect: function(iterator) {
    var result;
    this.each(function(value, index) {
      if (iterator(value, index)) {
        result = value;
        throw $break;
      }
    });
    return result;
  },

  findAll: function(iterator) {
    var results = [];
    this.each(function(value, index) {
      if (iterator(value, index))
        results.push(value);
    });
    return results;
  },

  grep: function(pattern, iterator) {
    var results = [];
    this.each(function(value, index) {
      var stringValue = value.toString();
      if (stringValue.match(pattern))
        results.push((iterator || Prototype.K)(value, index));
    })
    return results;
  },

  include: function(object) {
    var found = false;
    this.each(function(value) {
      if (value == object) {
        found = true;
        throw $break;
      }
    });
    return found;
  },

  inGroupsOf: function(number, fillWith) {
    fillWith = fillWith === undefined ? null : fillWith;
    return this.eachSlice(number, function(slice) {
      while(slice.length < number) slice.push(fillWith);
      return slice;
    });
  },

  inject: function(memo, iterator) {
    this.each(function(value, index) {
      memo = iterator(memo, value, index);
    });
    return memo;
  },

  invoke: function(method) {
    var args = $A(arguments).slice(1);
    return this.map(function(value) {
      return value[method].apply(value, args);
    });
  },

  max: function(iterator) {
    var result;
    this.each(function(value, index) {
      value = (iterator || Prototype.K)(value, index);
      if (result == undefined || value >= result)
        result = value;
    });
    return result;
  },

  min: function(iterator) {
    var result;
    this.each(function(value, index) {
      value = (iterator || Prototype.K)(value, index);
      if (result == undefined || value < result)
        result = value;
    });
    return result;
  },

  partition: function(iterator) {
    var trues = [], falses = [];
    this.each(function(value, index) {
      ((iterator || Prototype.K)(value, index) ?
        trues : falses).push(value);
    });
    return [trues, falses];
  },

  pluck: function(property) {
    var results = [];
    this.each(function(value, index) {
      results.push(value[property]);
    });
    return results;
  },

  reject: function(iterator) {
    var results = [];
    this.each(function(value, index) {
      if (!iterator(value, index))
        results.push(value);
    });
    return results;
  },

  sortBy: function(iterator) {
    return this.map(function(value, index) {
      return {value: value, criteria: iterator(value, index)};
    }).sort(function(left, right) {
      var a = left.criteria, b = right.criteria;
      return a < b ? -1 : a > b ? 1 : 0;
    }).pluck('value');
  },

  toArray: function() {
    return this.map();
  },

  zip: function() {
    var iterator = Prototype.K, args = $A(arguments);
    if (typeof args.last() == 'function')
      iterator = args.pop();

    var collections = [this].concat(args).map($A);
    return this.map(function(value, index) {
      return iterator(collections.pluck(index));
    });
  },

  size: function() {
    return this.toArray().length;
  },

  inspect: function() {
    return '#<Enumerable:' + this.toArray().inspect() + '>';
  }
}

Object.extend(Enumerable, {
  map:     Enumerable.collect,
  find:    Enumerable.detect,
  select:  Enumerable.findAll,
  member:  Enumerable.include,
  entries: Enumerable.toArray
});
var $A = Array.from = function(iterable) {
  if (!iterable) return [];
  if (iterable.toArray) {
    return iterable.toArray();
  } else {
    var results = [];
    for (var i = 0, length = iterable.length; i < length; i++)
      results.push(iterable[i]);
    return results;
  }
}

if (Prototype.Browser.WebKit) {
  $A = Array.from = function(iterable) {
    if (!iterable) return [];
    if (!(typeof iterable == 'function' && iterable == '[object NodeList]') &&
      iterable.toArray) {
      return iterable.toArray();
    } else {
      var results = [];
      for (var i = 0, length = iterable.length; i < length; i++)
        results.push(iterable[i]);
      return results;
    }
  }
}

Object.extend(Array.prototype, Enumerable);

if (!Array.prototype._reverse)
  Array.prototype._reverse = Array.prototype.reverse;

Object.extend(Array.prototype, {
  _each: function(iterator) {
    for (var i = 0, length = this.length; i < length; i++)
      iterator(this[i]);
  },

  clear: function() {
    this.length = 0;
    return this;
  },

  first: function() {
    return this[0];
  },

  last: function() {
    return this[this.length - 1];
  },

  compact: function() {
    return this.select(function(value) {
      return value != null;
    });
  },

  flatten: function() {
    return this.inject([], function(array, value) {
      return array.concat(value && value.constructor == Array ?
        value.flatten() : [value]);
    });
  },

  without: function() {
    var values = $A(arguments);
    return this.select(function(value) {
      return !values.include(value);
    });
  },

  indexOf: function(object) {
    for (var i = 0, length = this.length; i < length; i++)
      if (this[i] == object) return i;
    return -1;
  },

  reverse: function(inline) {
    return (inline !== false ? this : this.toArray())._reverse();
  },

  reduce: function() {
    return this.length > 1 ? this : this[0];
  },

  uniq: function(sorted) {
    return this.inject([], function(array, value, index) {
      if (0 == index || (sorted ? array.last() != value : !array.include(value)))
        array.push(value);
      return array;
    });
  },

  clone: function() {
    return [].concat(this);
  },

  size: function() {
    return this.length;
  },

  inspect: function() {
    return '[' + this.map(Object.inspect).join(', ') + ']';
  },

  toJSON: function() {
    var results = [];
    this.each(function(object) {
      var value = Object.toJSON(object);
      if (value !== undefined) results.push(value);
    });
    return '[' + results.join(', ') + ']';
  }
});

Array.prototype.toArray = Array.prototype.clone;

function $w(string) {
  string = string.strip();
  return string ? string.split(/\s+/) : [];
}

if (Prototype.Browser.Opera){
  Array.prototype.concat = function() {
    var array = [];
    for (var i = 0, length = this.length; i < length; i++) array.push(this[i]);
    for (var i = 0, length = arguments.length; i < length; i++) {
      if (arguments[i].constructor == Array) {
        for (var j = 0, arrayLength = arguments[i].length; j < arrayLength; j++)
          array.push(arguments[i][j]);
      } else {
        array.push(arguments[i]);
      }
    }
    return array;
  }
}
var Hash = function(object) {
  if (object instanceof Hash) this.merge(object);
  else Object.extend(this, object || {});
};

Object.extend(Hash, {
  toQueryString: function(obj) {
    var parts = [];
    parts.add = arguments.callee.addPair;

    this.prototype._each.call(obj, function(pair) {
      if (!pair.key) return;
      var value = pair.value;

      if (value && typeof value == 'object') {
        if (value.constructor == Array) value.each(function(value) {
          parts.add(pair.key, value);
        });
        return;
      }
      parts.add(pair.key, value);
    });

    return parts.join('&');
  },

  toJSON: function(object) {
    var results = [];
    this.prototype._each.call(object, function(pair) {
      var value = Object.toJSON(pair.value);
      if (value !== undefined) results.push(pair.key.toJSON() + ': ' + value);
    });
    return '{' + results.join(', ') + '}';
  }
});

Hash.toQueryString.addPair = function(key, value, prefix) {
  key = encodeURIComponent(key);
  if (value === undefined) this.push(key);
  else this.push(key + '=' + (value == null ? '' : encodeURIComponent(value)));
}

Object.extend(Hash.prototype, Enumerable);
Object.extend(Hash.prototype, {
  _each: function(iterator) {
    for (var key in this) {
      var value = this[key];
      if (value && value == Hash.prototype[key]) continue;

      var pair = [key, value];
      pair.key = key;
      pair.value = value;
      iterator(pair);
    }
  },

  keys: function() {
    return this.pluck('key');
  },

  values: function() {
    return this.pluck('value');
  },

  merge: function(hash) {
    return $H(hash).inject(this, function(mergedHash, pair) {
      mergedHash[pair.key] = pair.value;
      return mergedHash;
    });
  },

  remove: function() {
    var result;
    for(var i = 0, length = arguments.length; i < length; i++) {
      var value = this[arguments[i]];
      if (value !== undefined){
        if (result === undefined) result = value;
        else {
          if (result.constructor != Array) result = [result];
          result.push(value)
        }
      }
      delete this[arguments[i]];
    }
    return result;
  },

  toQueryString: function() {
    return Hash.toQueryString(this);
  },

  inspect: function() {
    return '#<Hash:{' + this.map(function(pair) {
      return pair.map(Object.inspect).join(': ');
    }).join(', ') + '}>';
  },

  toJSON: function() {
    return Hash.toJSON(this);
  }
});

function $H(object) {
  if (object instanceof Hash) return object;
  return new Hash(object);
};

// Safari iterates over shadowed properties
if (function() {
  var i = 0, Test = function(value) { this.key = value };
  Test.prototype.key = 'foo';
  for (var property in new Test('bar')) i++;
  return i > 1;
}()) Hash.prototype._each = function(iterator) {
  var cache = [];
  for (var key in this) {
    var value = this[key];
    if ((value && value == Hash.prototype[key]) || cache.include(key)) continue;
    cache.push(key);
    var pair = [key, value];
    pair.key = key;
    pair.value = value;
    iterator(pair);
  }
};
ObjectRange = Class.create();
Object.extend(ObjectRange.prototype, Enumerable);
Object.extend(ObjectRange.prototype, {
  initialize: function(start, end, exclusive) {
    this.start = start;
    this.end = end;
    this.exclusive = exclusive;
  },

  _each: function(iterator) {
    var value = this.start;
    while (this.include(value)) {
      iterator(value);
      value = value.succ();
    }
  },

  include: function(value) {
    if (value < this.start)
      return false;
    if (this.exclusive)
      return value < this.end;
    return value <= this.end;
  }
});

var $R = function(start, end, exclusive) {
  return new ObjectRange(start, end, exclusive);
}

var Ajax = {
  getTransport: function() {
    return Try.these(
      function() {return new XMLHttpRequest()},
      function() {return new ActiveXObject('Msxml2.XMLHTTP')},
      function() {return new ActiveXObject('Microsoft.XMLHTTP')}
    ) || false;
  },

  activeRequestCount: 0
}

Ajax.Responders = {
  responders: [],

  _each: function(iterator) {
    this.responders._each(iterator);
  },

  register: function(responder) {
    if (!this.include(responder))
      this.responders.push(responder);
  },

  unregister: function(responder) {
    this.responders = this.responders.without(responder);
  },

  dispatch: function(callback, request, transport, json) {
    this.each(function(responder) {
      if (typeof responder[callback] == 'function') {
        try {
          responder[callback].apply(responder, [request, transport, json]);
        } catch (e) {}
      }
    });
  }
};

Object.extend(Ajax.Responders, Enumerable);

Ajax.Responders.register({
  onCreate: function() {
    Ajax.activeRequestCount++;
  },
  onComplete: function() {
    Ajax.activeRequestCount--;
  }
});

Ajax.Base = function() {};
Ajax.Base.prototype = {
  setOptions: function(options) {
    this.options = {
      method:       'post',
      asynchronous: true,
      contentType:  'application/x-www-form-urlencoded',
      encoding:     'UTF-8',
      parameters:   ''
    }
    Object.extend(this.options, options || {});

    this.options.method = this.options.method.toLowerCase();
    if (typeof this.options.parameters == 'string')
      this.options.parameters = this.options.parameters.toQueryParams();
  }
}

Ajax.Request = Class.create();
Ajax.Request.Events =
  ['Uninitialized', 'Loading', 'Loaded', 'Interactive', 'Complete'];

Ajax.Request.prototype = Object.extend(new Ajax.Base(), {
  _complete: false,

  initialize: function(url, options) {
    this.transport = Ajax.getTransport();
    this.setOptions(options);
    this.request(url);
  },

  request: function(url) {
    this.url = url;
    this.method = this.options.method;
    var params = Object.clone(this.options.parameters);

    if (!['get', 'post'].include(this.method)) {
      // simulate other verbs over post
      params['_method'] = this.method;
      this.method = 'post';
    }

    this.parameters = params;

    if (params = Hash.toQueryString(params)) {
      // when GET, append parameters to URL
      if (this.method == 'get')
        this.url += (this.url.include('?') ? '&' : '?') + params;
      else if (/Konqueror|Safari|KHTML/.test(navigator.userAgent))
        params += '&_=';
    }

    try {
      if (this.options.onCreate) this.options.onCreate(this.transport);
      Ajax.Responders.dispatch('onCreate', this, this.transport);

      this.transport.open(this.method.toUpperCase(), this.url,
        this.options.asynchronous);

      if (this.options.asynchronous)
        setTimeout(function() { this.respondToReadyState(1) }.bind(this), 10);

      this.transport.onreadystatechange = this.onStateChange.bind(this);
      this.setRequestHeaders();

      this.body = this.method == 'post' ? (this.options.postBody || params) : null;
      this.transport.send(this.body);

      /* Force Firefox to handle ready state 4 for synchronous requests */
      if (!this.options.asynchronous && this.transport.overrideMimeType)
        this.onStateChange();

    }
    catch (e) {
      this.dispatchException(e);
    }
  },

  onStateChange: function() {
    var readyState = this.transport.readyState;
    if (readyState > 1 && !((readyState == 4) && this._complete))
      this.respondToReadyState(this.transport.readyState);
  },

  setRequestHeaders: function() {
    var headers = {
      'X-Requested-With': 'XMLHttpRequest',
      'X-Prototype-Version': Prototype.Version,
      'Accept': 'text/javascript, text/html, application/xml, text/xml, */*'
    };

    if (this.method == 'post') {
      headers['Content-type'] = this.options.contentType +
        (this.options.encoding ? '; charset=' + this.options.encoding : '');

      /* Force "Connection: close" for older Mozilla browsers to work
       * around a bug where XMLHttpRequest sends an incorrect
       * Content-length header. See Mozilla Bugzilla #246651.
       */
      if (this.transport.overrideMimeType &&
          (navigator.userAgent.match(/Gecko\/(\d{4})/) || [0,2005])[1] < 2005)
            headers['Connection'] = 'close';
    }

    // user-defined headers
    if (typeof this.options.requestHeaders == 'object') {
      var extras = this.options.requestHeaders;

      if (typeof extras.push == 'function')
        for (var i = 0, length = extras.length; i < length; i += 2)
          headers[extras[i]] = extras[i+1];
      else
        $H(extras).each(function(pair) { headers[pair.key] = pair.value });
    }

    for (var name in headers)
      this.transport.setRequestHeader(name, headers[name]);
  },

  success: function() {
    return !this.transport.status
        || (this.transport.status >= 200 && this.transport.status < 300);
  },

  respondToReadyState: function(readyState) {
    var state = Ajax.Request.Events[readyState];
    var transport = this.transport, json = this.evalJSON();

    if (state == 'Complete') {
      try {
        this._complete = true;
        (this.options['on' + this.transport.status]
         || this.options['on' + (this.success() ? 'Success' : 'Failure')]
         || Prototype.emptyFunction)(transport, json);
      } catch (e) {
        this.dispatchException(e);
      }

      var contentType = this.getHeader('Content-type');
      if (contentType && contentType.strip().
        match(/^(text|application)\/(x-)?(java|ecma)script(;.*)?$/i))
          this.evalResponse();
    }

    try {
      (this.options['on' + state] || Prototype.emptyFunction)(transport, json);
      Ajax.Responders.dispatch('on' + state, this, transport, json);
    } catch (e) {
      this.dispatchException(e);
    }

    if (state == 'Complete') {
      // avoid memory leak in MSIE: clean up
      this.transport.onreadystatechange = Prototype.emptyFunction;
    }
  },

  getHeader: function(name) {
    try {
      return this.transport.getResponseHeader(name);
    } catch (e) { return null }
  },

  evalJSON: function() {
    try {
      var json = this.getHeader('X-JSON');
      return json ? json.evalJSON() : null;
    } catch (e) { return null }
  },

  evalResponse: function() {
    try {
      return eval((this.transport.responseText || '').unfilterJSON());
    } catch (e) {
      this.dispatchException(e);
    }
  },

  dispatchException: function(exception) {
    (this.options.onException || Prototype.emptyFunction)(this, exception);
    Ajax.Responders.dispatch('onException', this, exception);
  }
});

Ajax.Updater = Class.create();

Object.extend(Object.extend(Ajax.Updater.prototype, Ajax.Request.prototype), {
  initialize: function(container, url, options) {
    this.container = {
      success: (container.success || container),
      failure: (container.failure || (container.success ? null : container))
    }

    this.transport = Ajax.getTransport();
    this.setOptions(options);

    var onComplete = this.options.onComplete || Prototype.emptyFunction;
    this.options.onComplete = (function(transport, param) {
      this.updateContent();
      onComplete(transport, param);
    }).bind(this);

    this.request(url);
  },

  updateContent: function() {
    var receiver = this.container[this.success() ? 'success' : 'failure'];
    var response = this.transport.responseText;

    if (!this.options.evalScripts) response = response.stripScripts();

    if (receiver = $(receiver)) {
      if (this.options.insertion)
        new this.options.insertion(receiver, response);
      else
        receiver.update(response);
    }

    if (this.success()) {
      if (this.onComplete)
        setTimeout(this.onComplete.bind(this), 10);
    }
  }
});

Ajax.PeriodicalUpdater = Class.create();
Ajax.PeriodicalUpdater.prototype = Object.extend(new Ajax.Base(), {
  initialize: function(container, url, options) {
    this.setOptions(options);
    this.onComplete = this.options.onComplete;

    this.frequency = (this.options.frequency || 2);
    this.decay = (this.options.decay || 1);

    this.updater = {};
    this.container = container;
    this.url = url;

    this.start();
  },

  start: function() {
    this.options.onComplete = this.updateComplete.bind(this);
    this.onTimerEvent();
  },

  stop: function() {
    this.updater.options.onComplete = undefined;
    clearTimeout(this.timer);
    (this.onComplete || Prototype.emptyFunction).apply(this, arguments);
  },

  updateComplete: function(request) {
    if (this.options.decay) {
      this.decay = (request.responseText == this.lastText ?
        this.decay * this.options.decay : 1);

      this.lastText = request.responseText;
    }
    this.timer = setTimeout(this.onTimerEvent.bind(this),
      this.decay * this.frequency * 1000);
  },

  onTimerEvent: function() {
    this.updater = new Ajax.Updater(this.container, this.url, this.options);
  }
});
function $(element) {
  if (arguments.length > 1) {
    for (var i = 0, elements = [], length = arguments.length; i < length; i++)
      elements.push($(arguments[i]));
    return elements;
  }
  if (typeof element == 'string')
    element = document.getElementById(element);
  return Element.extend(element);
}

if (Prototype.BrowserFeatures.XPath) {
  document._getElementsByXPath = function(expression, parentElement) {
    var results = [];
    var query = document.evaluate(expression, $(parentElement) || document,
      null, XPathResult.ORDERED_NODE_SNAPSHOT_TYPE, null);
    for (var i = 0, length = query.snapshotLength; i < length; i++)
      results.push(query.snapshotItem(i));
    return results;
  };

  document.getElementsByClassName = function(className, parentElement) {
    var q = ".//*[contains(concat(' ', @class, ' '), ' " + className + " ')]";
    return document._getElementsByXPath(q, parentElement);
  }

} else document.getElementsByClassName = function(className, parentElement) {
  var children = ($(parentElement) || document.body).getElementsByTagName('*');
  var elements = [], child;
  for (var i = 0, length = children.length; i < length; i++) {
    child = children[i];
    if (Element.hasClassName(child, className))
      elements.push(Element.extend(child));
  }
  return elements;
};

/*--------------------------------------------------------------------------*/

if (!window.Element) var Element = {};

Element.extend = function(element) {
  var F = Prototype.BrowserFeatures;
  if (!element || !element.tagName || element.nodeType == 3 ||
   element._extended || F.SpecificElementExtensions || element == window)
    return element;

  var methods = {}, tagName = element.tagName, cache = Element.extend.cache,
   T = Element.Methods.ByTag;

  // extend methods for all tags (Safari doesn't need this)
  if (!F.ElementExtensions) {
    Object.extend(methods, Element.Methods),
    Object.extend(methods, Element.Methods.Simulated);
  }

  // extend methods for specific tags
  if (T[tagName]) Object.extend(methods, T[tagName]);

  for (var property in methods) {
    var value = methods[property];
    if (typeof value == 'function' && !(property in element))
      element[property] = cache.findOrStore(value);
  }

  element._extended = Prototype.emptyFunction;
  return element;
};

Element.extend.cache = {
  findOrStore: function(value) {
    return this[value] = this[value] || function() {
      return value.apply(null, [this].concat($A(arguments)));
    }
  }
};

Element.Methods = {
  visible: function(element) {
    return $(element).style.display != 'none';
  },

  toggle: function(element) {
    element = $(element);
    Element[Element.visible(element) ? 'hide' : 'show'](element);
    return element;
  },

  hide: function(element) {
    $(element).style.display = 'none';
    return element;
  },

  show: function(element) {
    $(element).style.display = '';
    return element;
  },

  remove: function(element) {
    element = $(element);
    element.parentNode.removeChild(element);
    return element;
  },

  update: function(element, html) {
    html = typeof html == 'undefined' ? '' : html.toString();
    $(element).innerHTML = html.stripScripts();
    setTimeout(function() {html.evalScripts()}, 10);
    return element;
  },

  replace: function(element, html) {
    element = $(element);
    html = typeof html == 'undefined' ? '' : html.toString();
    if (element.outerHTML) {
      element.outerHTML = html.stripScripts();
    } else {
      var range = element.ownerDocument.createRange();
      range.selectNodeContents(element);
      element.parentNode.replaceChild(
        range.createContextualFragment(html.stripScripts()), element);
    }
    setTimeout(function() {html.evalScripts()}, 10);
    return element;
  },

  inspect: function(element) {
    element = $(element);
    var result = '<' + element.tagName.toLowerCase();
    $H({'id': 'id', 'className': 'class'}).each(function(pair) {
      var property = pair.first(), attribute = pair.last();
      var value = (element[property] || '').toString();
      if (value) result += ' ' + attribute + '=' + value.inspect(true);
    });
    return result + '>';
  },

  recursivelyCollect: function(element, property) {
    element = $(element);
    var elements = [];
    while (element = element[property])
      if (element.nodeType == 1)
        elements.push(Element.extend(element));
    return elements;
  },

  ancestors: function(element) {
    return $(element).recursivelyCollect('parentNode');
  },

  descendants: function(element) {
    return $A($(element).getElementsByTagName('*')).each(Element.extend);
  },

  firstDescendant: function(element) {
    element = $(element).firstChild;
    while (element && element.nodeType != 1) element = element.nextSibling;
    return $(element);
  },

  immediateDescendants: function(element) {
    if (!(element = $(element).firstChild)) return [];
    while (element && element.nodeType != 1) element = element.nextSibling;
    if (element) return [element].concat($(element).nextSiblings());
    return [];
  },

  previousSiblings: function(element) {
    return $(element).recursivelyCollect('previousSibling');
  },

  nextSiblings: function(element) {
    return $(element).recursivelyCollect('nextSibling');
  },

  siblings: function(element) {
    element = $(element);
    return element.previousSiblings().reverse().concat(element.nextSiblings());
  },

  match: function(element, selector) {
    if (typeof selector == 'string')
      selector = new Selector(selector);
    return selector.match($(element));
  },

  up: function(element, expression, index) {
    element = $(element);
    if (arguments.length == 1) return $(element.parentNode);
    var ancestors = element.ancestors();
    return expression ? Selector.findElement(ancestors, expression, index) :
      ancestors[index || 0];
  },

  down: function(element, expression, index) {
    element = $(element);
    if (arguments.length == 1) return element.firstDescendant();
    var descendants = element.descendants();
    return expression ? Selector.findElement(descendants, expression, index) :
      descendants[index || 0];
  },

  previous: function(element, expression, index) {
    element = $(element);
    if (arguments.length == 1) return $(Selector.handlers.previousElementSibling(element));
    var previousSiblings = element.previousSiblings();
    return expression ? Selector.findElement(previousSiblings, expression, index) :
      previousSiblings[index || 0];
  },

  next: function(element, expression, index) {
    element = $(element);
    if (arguments.length == 1) return $(Selector.handlers.nextElementSibling(element));
    var nextSiblings = element.nextSiblings();
    return expression ? Selector.findElement(nextSiblings, expression, index) :
      nextSiblings[index || 0];
  },

  getElementsBySelector: function() {
    var args = $A(arguments), element = $(args.shift());
    return Selector.findChildElements(element, args);
  },

  getElementsByClassName: function(element, className) {
    return document.getElementsByClassName(className, element);
  },

  readAttribute: function(element, name) {
    element = $(element);
    if (Prototype.Browser.IE) {
      if (!element.attributes) return null;
      var t = Element._attributeTranslations;
      if (t.values[name]) return t.values[name](element, name);
      if (t.names[name])  name = t.names[name];
      var attribute = element.attributes[name];
      return attribute ? attribute.nodeValue : null;
    }
    return element.getAttribute(name);
  },

  getHeight: function(element) {
    return $(element).getDimensions().height;
  },

  getWidth: function(element) {
    return $(element).getDimensions().width;
  },

  classNames: function(element) {
    return new Element.ClassNames(element);
  },

  hasClassName: function(element, className) {
    if (!(element = $(element))) return;
    var elementClassName = element.className;
    if (elementClassName.length == 0) return false;
    if (elementClassName == className ||
        elementClassName.match(new RegExp("(^|\\s)" + className + "(\\s|$)")))
      return true;
    return false;
  },

  addClassName: function(element, className) {
    if (!(element = $(element))) return;
    Element.classNames(element).add(className);
    return element;
  },

  removeClassName: function(element, className) {
    if (!(element = $(element))) return;
    Element.classNames(element).remove(className);
    return element;
  },

  toggleClassName: function(element, className) {
    if (!(element = $(element))) return;
    Element.classNames(element)[element.hasClassName(className) ? 'remove' : 'add'](className);
    return element;
  },

  observe: function() {
    Event.observe.apply(Event, arguments);
    return $A(arguments).first();
  },

  stopObserving: function() {
    Event.stopObserving.apply(Event, arguments);
    return $A(arguments).first();
  },

  // removes whitespace-only text node children
  cleanWhitespace: function(element) {
    element = $(element);
    var node = element.firstChild;
    while (node) {
      var nextNode = node.nextSibling;
      if (node.nodeType == 3 && !/\S/.test(node.nodeValue))
        element.removeChild(node);
      node = nextNode;
    }
    return element;
  },

  empty: function(element) {
    return $(element).innerHTML.blank();
  },

  descendantOf: function(element, ancestor) {
    element = $(element), ancestor = $(ancestor);
    while (element = element.parentNode)
      if (element == ancestor) return true;
    return false;
  },

  scrollTo: function(element) {
    element = $(element);
    var pos = Position.cumulativeOffset(element);
    window.scrollTo(pos[0], pos[1]);
    return element;
  },

  getStyle: function(element, style) {
    element = $(element);
    style = style == 'float' ? 'cssFloat' : style.camelize();
    var value = element.style[style];
    if (!value) {
      var css = document.defaultView.getComputedStyle(element, null);
      value = css ? css[style] : null;
    }
    if (style == 'opacity') return value ? parseFloat(value) : 1.0;
    return value == 'auto' ? null : value;
  },

  getOpacity: function(element) {
    return $(element).getStyle('opacity');
  },

  setStyle: function(element, styles, camelized) {
    element = $(element);
    var elementStyle = element.style;

    for (var property in styles)
      if (property == 'opacity') element.setOpacity(styles[property])
      else
        elementStyle[(property == 'float' || property == 'cssFloat') ?
          (elementStyle.styleFloat === undefined ? 'cssFloat' : 'styleFloat') :
          (camelized ? property : property.camelize())] = styles[property];

    return element;
  },

  setOpacity: function(element, value) {
    element = $(element);
    element.style.opacity = (value == 1 || value === '') ? '' :
      (value < 0.00001) ? 0 : value;
    return element;
  },

  getDimensions: function(element) {
    element = $(element);
    var display = $(element).getStyle('display');
    if (display != 'none' && display != null) // Safari bug
      return {width: element.offsetWidth, height: element.offsetHeight};

    // All *Width and *Height properties give 0 on elements with display none,
    // so enable the element temporarily
    var els = element.style;
    var originalVisibility = els.visibility;
    var originalPosition = els.position;
    var originalDisplay = els.display;
    els.visibility = 'hidden';
    els.position = 'absolute';
    els.display = 'block';
    var originalWidth = element.clientWidth;
    var originalHeight = element.clientHeight;
    els.display = originalDisplay;
    els.position = originalPosition;
    els.visibility = originalVisibility;
    return {width: originalWidth, height: originalHeight};
  },

  makePositioned: function(element) {
    element = $(element);
    var pos = Element.getStyle(element, 'position');
    if (pos == 'static' || !pos) {
      element._madePositioned = true;
      element.style.position = 'relative';
      // Opera returns the offset relative to the positioning context, when an
      // element is position relative but top and left have not been defined
      if (window.opera) {
        element.style.top = 0;
        element.style.left = 0;
      }
    }
    return element;
  },

  undoPositioned: function(element) {
    element = $(element);
    if (element._madePositioned) {
      element._madePositioned = undefined;
      element.style.position =
        element.style.top =
        element.style.left =
        element.style.bottom =
        element.style.right = '';
    }
    return element;
  },

  makeClipping: function(element) {
    element = $(element);
    if (element._overflow) return element;
    element._overflow = element.style.overflow || 'auto';
    if ((Element.getStyle(element, 'overflow') || 'visible') != 'hidden')
      element.style.overflow = 'hidden';
    return element;
  },

  undoClipping: function(element) {
    element = $(element);
    if (!element._overflow) return element;
    element.style.overflow = element._overflow == 'auto' ? '' : element._overflow;
    element._overflow = null;
    return element;
  }
};

Object.extend(Element.Methods, {
  childOf: Element.Methods.descendantOf,
  childElements: Element.Methods.immediateDescendants
});

if (Prototype.Browser.Opera) {
  Element.Methods._getStyle = Element.Methods.getStyle;
  Element.Methods.getStyle = function(element, style) {
    switch(style) {
      case 'left':
      case 'top':
      case 'right':
      case 'bottom':
        if (Element._getStyle(element, 'position') == 'static') return null;
      default: return Element._getStyle(element, style);
    }
  };
}
else if (Prototype.Browser.IE) {
  Element.Methods.getStyle = function(element, style) {
    element = $(element);
    style = (style == 'float' || style == 'cssFloat') ? 'styleFloat' : style.camelize();
    var value = element.style[style];
    if (!value && element.currentStyle) value = element.currentStyle[style];

    if (style == 'opacity') {
      if (value = (element.getStyle('filter') || '').match(/alpha\(opacity=(.*)\)/))
        if (value[1]) return parseFloat(value[1]) / 100;
      return 1.0;
    }

    if (value == 'auto') {
      if ((style == 'width' || style == 'height') && (element.getStyle('display') != 'none'))
        return element['offset'+style.capitalize()] + 'px';
      return null;
    }
    return value;
  };

  Element.Methods.setOpacity = function(element, value) {
    element = $(element);
    var filter = element.getStyle('filter'), style = element.style;
    if (value == 1 || value === '') {
      style.filter = filter.replace(/alpha\([^\)]*\)/gi,'');
      return element;
    } else if (value < 0.00001) value = 0;
    style.filter = filter.replace(/alpha\([^\)]*\)/gi, '') +
      'alpha(opacity=' + (value * 100) + ')';
    return element;
  };

  // IE is missing .innerHTML support for TABLE-related elements
  Element.Methods.update = function(element, html) {
    element = $(element);
    html = typeof html == 'undefined' ? '' : html.toString();
    var tagName = element.tagName.toUpperCase();
    if (['THEAD','TBODY','TR','TD'].include(tagName)) {
      var div = document.createElement('div');
      switch (tagName) {
        case 'THEAD':
        case 'TBODY':
          div.innerHTML = '<table><tbody>' +  html.stripScripts() + '</tbody></table>';
          depth = 2;
          break;
        case 'TR':
          div.innerHTML = '<table><tbody><tr>' +  html.stripScripts() + '</tr></tbody></table>';
          depth = 3;
          break;
        case 'TD':
          div.innerHTML = '<table><tbody><tr><td>' +  html.stripScripts() + '</td></tr></tbody></table>';
          depth = 4;
      }
      $A(element.childNodes).each(function(node) { element.removeChild(node) });
      depth.times(function() { div = div.firstChild });
      $A(div.childNodes).each(function(node) { element.appendChild(node) });
    } else {
      element.innerHTML = html.stripScripts();
    }
    setTimeout(function() { html.evalScripts() }, 10);
    return element;
  }
}
else if (Prototype.Browser.Gecko) {
  Element.Methods.setOpacity = function(element, value) {
    element = $(element);
    element.style.opacity = (value == 1) ? 0.999999 :
      (value === '') ? '' : (value < 0.00001) ? 0 : value;
    return element;
  };
}

Element._attributeTranslations = {
  names: {
    colspan:   "colSpan",
    rowspan:   "rowSpan",
    valign:    "vAlign",
    datetime:  "dateTime",
    accesskey: "accessKey",
    tabindex:  "tabIndex",
    enctype:   "encType",
    maxlength: "maxLength",
    readonly:  "readOnly",
    longdesc:  "longDesc"
  },
  values: {
    _getAttr: function(element, attribute) {
      return element.getAttribute(attribute, 2);
    },
    _flag: function(element, attribute) {
      return $(element).hasAttribute(attribute) ? attribute : null;
    },
    style: function(element) {
      return element.style.cssText.toLowerCase();
    },
    title: function(element) {
      var node = element.getAttributeNode('title');
      return node.specified ? node.nodeValue : null;
    }
  }
};

(function() {
  Object.extend(this, {
    href: this._getAttr,
    src:  this._getAttr,
    type: this._getAttr,
    disabled: this._flag,
    checked:  this._flag,
    readonly: this._flag,
    multiple: this._flag
  });
}).call(Element._attributeTranslations.values);

Element.Methods.Simulated = {
  hasAttribute: function(element, attribute) {
    var t = Element._attributeTranslations, node;
    attribute = t.names[attribute] || attribute;
    node = $(element).getAttributeNode(attribute);
    return node && node.specified;
  }
};

Element.Methods.ByTag = {};

Object.extend(Element, Element.Methods);

if (!Prototype.BrowserFeatures.ElementExtensions &&
 document.createElement('div').__proto__) {
  window.HTMLElement = {};
  window.HTMLElement.prototype = document.createElement('div').__proto__;
  Prototype.BrowserFeatures.ElementExtensions = true;
}

Element.hasAttribute = function(element, attribute) {
  if (element.hasAttribute) return element.hasAttribute(attribute);
  return Element.Methods.Simulated.hasAttribute(element, attribute);
};

Element.addMethods = function(methods) {
  var F = Prototype.BrowserFeatures, T = Element.Methods.ByTag;

  if (!methods) {
    Object.extend(Form, Form.Methods);
    Object.extend(Form.Element, Form.Element.Methods);
    Object.extend(Element.Methods.ByTag, {
      "FORM":     Object.clone(Form.Methods),
      "INPUT":    Object.clone(Form.Element.Methods),
      "SELECT":   Object.clone(Form.Element.Methods),
      "TEXTAREA": Object.clone(Form.Element.Methods)
    });
  }

  if (arguments.length == 2) {
    var tagName = methods;
    methods = arguments[1];
  }

  if (!tagName) Object.extend(Element.Methods, methods || {});
  else {
    if (tagName.constructor == Array) tagName.each(extend);
    else extend(tagName);
  }

  function extend(tagName) {
    tagName = tagName.toUpperCase();
    if (!Element.Methods.ByTag[tagName])
      Element.Methods.ByTag[tagName] = {};
    Object.extend(Element.Methods.ByTag[tagName], methods);
  }

  function copy(methods, destination, onlyIfAbsent) {
    onlyIfAbsent = onlyIfAbsent || false;
    var cache = Element.extend.cache;
    for (var property in methods) {
      var value = methods[property];
      if (!onlyIfAbsent || !(property in destination))
        destination[property] = cache.findOrStore(value);
    }
  }

  function findDOMClass(tagName) {
    var klass;
    var trans = {
      "OPTGROUP": "OptGroup", "TEXTAREA": "TextArea", "P": "Paragraph",
      "FIELDSET": "FieldSet", "UL": "UList", "OL": "OList", "DL": "DList",
      "DIR": "Directory", "H1": "Heading", "H2": "Heading", "H3": "Heading",
      "H4": "Heading", "H5": "Heading", "H6": "Heading", "Q": "Quote",
      "INS": "Mod", "DEL": "Mod", "A": "Anchor", "IMG": "Image", "CAPTION":
      "TableCaption", "COL": "TableCol", "COLGROUP": "TableCol", "THEAD":
      "TableSection", "TFOOT": "TableSection", "TBODY": "TableSection", "TR":
      "TableRow", "TH": "TableCell", "TD": "TableCell", "FRAMESET":
      "FrameSet", "IFRAME": "IFrame"
    };
    if (trans[tagName]) klass = 'HTML' + trans[tagName] + 'Element';
    if (window[klass]) return window[klass];
    klass = 'HTML' + tagName + 'Element';
    if (window[klass]) return window[klass];
    klass = 'HTML' + tagName.capitalize() + 'Element';
    if (window[klass]) return window[klass];

    window[klass] = {};
    window[klass].prototype = document.createElement(tagName).__proto__;
    return window[klass];
  }

  if (F.ElementExtensions) {
    copy(Element.Methods, HTMLElement.prototype);
    copy(Element.Methods.Simulated, HTMLElement.prototype, true);
  }

  if (F.SpecificElementExtensions) {
    for (var tag in Element.Methods.ByTag) {
      var klass = findDOMClass(tag);
      if (typeof klass == "undefined") continue;
      copy(T[tag], klass.prototype);
    }
  }

  Object.extend(Element, Element.Methods);
  delete Element.ByTag;
};

var Toggle = { display: Element.toggle };

/*--------------------------------------------------------------------------*/

Abstract.Insertion = function(adjacency) {
  this.adjacency = adjacency;
}

Abstract.Insertion.prototype = {
  initialize: function(element, content) {
    this.element = $(element);
    this.content = content.stripScripts();

    if (this.adjacency && this.element.insertAdjacentHTML) {
      try {
        this.element.insertAdjacentHTML(this.adjacency, this.content);
      } catch (e) {
        var tagName = this.element.tagName.toUpperCase();
        if (['TBODY', 'TR'].include(tagName)) {
          this.insertContent(this.contentFromAnonymousTable());
        } else {
          throw e;
        }
      }
    } else {
      this.range = this.element.ownerDocument.createRange();
      if (this.initializeRange) this.initializeRange();
      this.insertContent([this.range.createContextualFragment(this.content)]);
    }

    setTimeout(function() {content.evalScripts()}, 10);
  },

  contentFromAnonymousTable: function() {
    var div = document.createElement('div');
    div.innerHTML = '<table><tbody>' + this.content + '</tbody></table>';
    return $A(div.childNodes[0].childNodes[0].childNodes);
  }
}

var Insertion = new Object();

Insertion.Before = Class.create();
Insertion.Before.prototype = Object.extend(new Abstract.Insertion('beforeBegin'), {
  initializeRange: function() {
    this.range.setStartBefore(this.element);
  },

  insertContent: function(fragments) {
    fragments.each((function(fragment) {
      this.element.parentNode.insertBefore(fragment, this.element);
    }).bind(this));
  }
});

Insertion.Top = Class.create();
Insertion.Top.prototype = Object.extend(new Abstract.Insertion('afterBegin'), {
  initializeRange: function() {
    this.range.selectNodeContents(this.element);
    this.range.collapse(true);
  },

  insertContent: function(fragments) {
    fragments.reverse(false).each((function(fragment) {
      this.element.insertBefore(fragment, this.element.firstChild);
    }).bind(this));
  }
});

Insertion.Bottom = Class.create();
Insertion.Bottom.prototype = Object.extend(new Abstract.Insertion('beforeEnd'), {
  initializeRange: function() {
    this.range.selectNodeContents(this.element);
    this.range.collapse(this.element);
  },

  insertContent: function(fragments) {
    fragments.each((function(fragment) {
      this.element.appendChild(fragment);
    }).bind(this));
  }
});

Insertion.After = Class.create();
Insertion.After.prototype = Object.extend(new Abstract.Insertion('afterEnd'), {
  initializeRange: function() {
    this.range.setStartAfter(this.element);
  },

  insertContent: function(fragments) {
    fragments.each((function(fragment) {
      this.element.parentNode.insertBefore(fragment,
        this.element.nextSibling);
    }).bind(this));
  }
});

/*--------------------------------------------------------------------------*/

Element.ClassNames = Class.create();
Element.ClassNames.prototype = {
  initialize: function(element) {
    this.element = $(element);
  },

  _each: function(iterator) {
    this.element.className.split(/\s+/).select(function(name) {
      return name.length > 0;
    })._each(iterator);
  },

  set: function(className) {
    this.element.className = className;
  },

  add: function(classNameToAdd) {
    if (this.include(classNameToAdd)) return;
    this.set($A(this).concat(classNameToAdd).join(' '));
  },

  remove: function(classNameToRemove) {
    if (!this.include(classNameToRemove)) return;
    this.set($A(this).without(classNameToRemove).join(' '));
  },

  toString: function() {
    return $A(this).join(' ');
  }
};

Object.extend(Element.ClassNames.prototype, Enumerable);
/* Portions of the Selector class are derived from Jack Slocum’s DomQuery,
 * part of YUI-Ext version 0.40, distributed under the terms of an MIT-style
 * license.  Please see http://www.yui-ext.com/ for more information. */

var Selector = Class.create();

Selector.prototype = {
  initialize: function(expression) {
    this.expression = expression.strip();
    this.compileMatcher();
  },

  compileMatcher: function() {
    // Selectors with namespaced attributes can't use the XPath version
    if (Prototype.BrowserFeatures.XPath && !(/\[[\w-]*?:/).test(this.expression))
      return this.compileXPathMatcher();

    var e = this.expression, ps = Selector.patterns, h = Selector.handlers,
        c = Selector.criteria, le, p, m;

    if (Selector._cache[e]) {
      this.matcher = Selector._cache[e]; return;
    }
    this.matcher = ["this.matcher = function(root) {",
                    "var r = root, h = Selector.handlers, c = false, n;"];

    while (e && le != e && (/\S/).test(e)) {
      le = e;
      for (var i in ps) {
        p = ps[i];
        if (m = e.match(p)) {
          this.matcher.push(typeof c[i] == 'function' ? c[i](m) :
    	      new Template(c[i]).evaluate(m));
          e = e.replace(m[0], '');
          break;
        }
      }
    }

    this.matcher.push("return h.unique(n);\n}");
    eval(this.matcher.join('\n'));
    Selector._cache[this.expression] = this.matcher;
  },

  compileXPathMatcher: function() {
    var e = this.expression, ps = Selector.patterns,
        x = Selector.xpath, le,  m;

    if (Selector._cache[e]) {
      this.xpath = Selector._cache[e]; return;
    }

    this.matcher = ['.//*'];
    while (e && le != e && (/\S/).test(e)) {
      le = e;
      for (var i in ps) {
        if (m = e.match(ps[i])) {
          this.matcher.push(typeof x[i] == 'function' ? x[i](m) :
            new Template(x[i]).evaluate(m));
          e = e.replace(m[0], '');
          break;
        }
      }
    }

    this.xpath = this.matcher.join('');
    Selector._cache[this.expression] = this.xpath;
  },

  findElements: function(root) {
    root = root || document;
    if (this.xpath) return document._getElementsByXPath(this.xpath, root);
    return this.matcher(root);
  },

  match: function(element) {
    return this.findElements(document).include(element);
  },

  toString: function() {
    return this.expression;
  },

  inspect: function() {
    return "#<Selector:" + this.expression.inspect() + ">";
  }
};

Object.extend(Selector, {
  _cache: {},

  xpath: {
    descendant:   "//*",
    child:        "/*",
    adjacent:     "/following-sibling::*[1]",
    laterSibling: '/following-sibling::*',
    tagName:      function(m) {
      if (m[1] == '*') return '';
      return "[local-name()='" + m[1].toLowerCase() +
             "' or local-name()='" + m[1].toUpperCase() + "']";
    },
    className:    "[contains(concat(' ', @class, ' '), ' #{1} ')]",
    id:           "[@id='#{1}']",
    attrPresence: "[@#{1}]",
    attr: function(m) {
      m[3] = m[5] || m[6];
      return new Template(Selector.xpath.operators[m[2]]).evaluate(m);
    },
    pseudo: function(m) {
      var h = Selector.xpath.pseudos[m[1]];
      if (!h) return '';
      if (typeof h === 'function') return h(m);
      return new Template(Selector.xpath.pseudos[m[1]]).evaluate(m);
    },
    operators: {
      '=':  "[@#{1}='#{3}']",
      '!=': "[@#{1}!='#{3}']",
      '^=': "[starts-with(@#{1}, '#{3}')]",
      '$=': "[substring(@#{1}, (string-length(@#{1}) - string-length('#{3}') + 1))='#{3}']",
      '*=': "[contains(@#{1}, '#{3}')]",
      '~=': "[contains(concat(' ', @#{1}, ' '), ' #{3} ')]",
      '|=': "[contains(concat('-', @#{1}, '-'), '-#{3}-')]"
    },
    pseudos: {
      'first-child': '[not(preceding-sibling::*)]',
      'last-child':  '[not(following-sibling::*)]',
      'only-child':  '[not(preceding-sibling::* or following-sibling::*)]',
      'empty':       "[count(*) = 0 and (count(text()) = 0 or translate(text(), ' \t\r\n', '') = '')]",
      'checked':     "[@checked]",
      'disabled':    "[@disabled]",
      'enabled':     "[not(@disabled)]",
      'not': function(m) {
        var e = m[6], p = Selector.patterns,
            x = Selector.xpath, le, m, v;

        var exclusion = [];
        while (e && le != e && (/\S/).test(e)) {
          le = e;
          for (var i in p) {
            if (m = e.match(p[i])) {
              v = typeof x[i] == 'function' ? x[i](m) : new Template(x[i]).evaluate(m);
              exclusion.push("(" + v.substring(1, v.length - 1) + ")");
              e = e.replace(m[0], '');
              break;
            }
          }
        }
        return "[not(" + exclusion.join(" and ") + ")]";
      },
      'nth-child':      function(m) {
        return Selector.xpath.pseudos.nth("(count(./preceding-sibling::*) + 1) ", m);
      },
      'nth-last-child': function(m) {
        return Selector.xpath.pseudos.nth("(count(./following-sibling::*) + 1) ", m);
      },
      'nth-of-type':    function(m) {
        return Selector.xpath.pseudos.nth("position() ", m);
      },
      'nth-last-of-type': function(m) {
        return Selector.xpath.pseudos.nth("(last() + 1 - position()) ", m);
      },
      'first-of-type':  function(m) {
        m[6] = "1"; return Selector.xpath.pseudos['nth-of-type'](m);
      },
      'last-of-type':   function(m) {
        m[6] = "1"; return Selector.xpath.pseudos['nth-last-of-type'](m);
      },
      'only-of-type':   function(m) {
        var p = Selector.xpath.pseudos; return p['first-of-type'](m) + p['last-of-type'](m);
      },
      nth: function(fragment, m) {
        var mm, formula = m[6], predicate;
        if (formula == 'even') formula = '2n+0';
        if (formula == 'odd')  formula = '2n+1';
        if (mm = formula.match(/^(\d+)$/)) // digit only
          return '[' + fragment + "= " + mm[1] + ']';
        if (mm = formula.match(/^(-?\d*)?n(([+-])(\d+))?/)) { // an+b
          if (mm[1] == "-") mm[1] = -1;
          var a = mm[1] ? Number(mm[1]) : 1;
          var b = mm[2] ? Number(mm[2]) : 0;
          predicate = "[((#{fragment} - #{b}) mod #{a} = 0) and " +
          "((#{fragment} - #{b}) div #{a} >= 0)]";
          return new Template(predicate).evaluate({
            fragment: fragment, a: a, b: b });
        }
      }
    }
  },

  criteria: {
    tagName:      'n = h.tagName(n, r, "#{1}", c);   c = false;',
    className:    'n = h.className(n, r, "#{1}", c); c = false;',
    id:           'n = h.id(n, r, "#{1}", c);        c = false;',
    attrPresence: 'n = h.attrPresence(n, r, "#{1}"); c = false;',
    attr: function(m) {
      m[3] = (m[5] || m[6]);
      return new Template('n = h.attr(n, r, "#{1}", "#{3}", "#{2}"); c = false;').evaluate(m);
    },
    pseudo:       function(m) {
      if (m[6]) m[6] = m[6].replace(/"/g, '\\"');
      return new Template('n = h.pseudo(n, "#{1}", "#{6}", r, c); c = false;').evaluate(m);
    },
    descendant:   'c = "descendant";',
    child:        'c = "child";',
    adjacent:     'c = "adjacent";',
    laterSibling: 'c = "laterSibling";'
  },

  patterns: {
    // combinators must be listed first
    // (and descendant needs to be last combinator)
    laterSibling: /^\s*~\s*/,
    child:        /^\s*>\s*/,
    adjacent:     /^\s*\+\s*/,
    descendant:   /^\s/,

    // selectors follow
    tagName:      /^\s*(\*|[\w\-]+)(\b|$)?/,
    id:           /^#([\w\-\*]+)(\b|$)/,
    className:    /^\.([\w\-\*]+)(\b|$)/,
    pseudo:       /^:((first|last|nth|nth-last|only)(-child|-of-type)|empty|checked|(en|dis)abled|not)(\((.*?)\))?(\b|$|\s|(?=:))/,
    attrPresence: /^\[([\w]+)\]/,
    attr:         /\[((?:[\w-]*:)?[\w-]+)\s*(?:([!^$*~|]?=)\s*((['"])([^\]]*?)\4|([^'"][^\]]*?)))?\]/
  },

  handlers: {
    // UTILITY FUNCTIONS
    // joins two collections
    concat: function(a, b) {
      for (var i = 0, node; node = b[i]; i++)
        a.push(node);
      return a;
    },

    // marks an array of nodes for counting
    mark: function(nodes) {
      for (var i = 0, node; node = nodes[i]; i++)
        node._counted = true;
      return nodes;
    },

    unmark: function(nodes) {
      for (var i = 0, node; node = nodes[i]; i++)
        node._counted = undefined;
      return nodes;
    },

    // mark each child node with its position (for nth calls)
    // "ofType" flag indicates whether we're indexing for nth-of-type
    // rather than nth-child
    index: function(parentNode, reverse, ofType) {
      parentNode._counted = true;
      if (reverse) {
        for (var nodes = parentNode.childNodes, i = nodes.length - 1, j = 1; i >= 0; i--) {
          node = nodes[i];
          if (node.nodeType == 1 && (!ofType || node._counted)) node.nodeIndex = j++;
        }
      } else {
        for (var i = 0, j = 1, nodes = parentNode.childNodes; node = nodes[i]; i++)
          if (node.nodeType == 1 && (!ofType || node._counted)) node.nodeIndex = j++;
      }
    },

    // filters out duplicates and extends all nodes
    unique: function(nodes) {
      if (nodes.length == 0) return nodes;
      var results = [], n;
      for (var i = 0, l = nodes.length; i < l; i++)
        if (!(n = nodes[i])._counted) {
          n._counted = true;
          results.push(Element.extend(n));
        }
      return Selector.handlers.unmark(results);
    },

    // COMBINATOR FUNCTIONS
    descendant: function(nodes) {
      var h = Selector.handlers;
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        h.concat(results, node.getElementsByTagName('*'));
      return results;
    },

    child: function(nodes) {
      var h = Selector.handlers;
      for (var i = 0, results = [], node; node = nodes[i]; i++) {
        for (var j = 0, children = [], child; child = node.childNodes[j]; j++)
          if (child.nodeType == 1 && child.tagName != '!') results.push(child);
      }
      return results;
    },

    adjacent: function(nodes) {
      for (var i = 0, results = [], node; node = nodes[i]; i++) {
        var next = this.nextElementSibling(node);
        if (next) results.push(next);
      }
      return results;
    },

    laterSibling: function(nodes) {
      var h = Selector.handlers;
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        h.concat(results, Element.nextSiblings(node));
      return results;
    },

    nextElementSibling: function(node) {
      while (node = node.nextSibling)
	      if (node.nodeType == 1) return node;
      return null;
    },

    previousElementSibling: function(node) {
      while (node = node.previousSibling)
        if (node.nodeType == 1) return node;
      return null;
    },

    // TOKEN FUNCTIONS
    tagName: function(nodes, root, tagName, combinator) {
      tagName = tagName.toUpperCase();
      var results = [], h = Selector.handlers;
      if (nodes) {
        if (combinator) {
          // fastlane for ordinary descendant combinators
          if (combinator == "descendant") {
            for (var i = 0, node; node = nodes[i]; i++)
              h.concat(results, node.getElementsByTagName(tagName));
            return results;
          } else nodes = this[combinator](nodes);
          if (tagName == "*") return nodes;
        }
        for (var i = 0, node; node = nodes[i]; i++)
          if (node.tagName.toUpperCase() == tagName) results.push(node);
        return results;
      } else return root.getElementsByTagName(tagName);
    },

    id: function(nodes, root, id, combinator) {
      var targetNode = $(id), h = Selector.handlers;
      if (!nodes && root == document) return targetNode ? [targetNode] : [];
      if (nodes) {
        if (combinator) {
          if (combinator == 'child') {
            for (var i = 0, node; node = nodes[i]; i++)
              if (targetNode.parentNode == node) return [targetNode];
          } else if (combinator == 'descendant') {
            for (var i = 0, node; node = nodes[i]; i++)
              if (Element.descendantOf(targetNode, node)) return [targetNode];
          } else if (combinator == 'adjacent') {
            for (var i = 0, node; node = nodes[i]; i++)
              if (Selector.handlers.previousElementSibling(targetNode) == node)
                return [targetNode];
          } else nodes = h[combinator](nodes);
        }
        for (var i = 0, node; node = nodes[i]; i++)
          if (node == targetNode) return [targetNode];
        return [];
      }
      return (targetNode && Element.descendantOf(targetNode, root)) ? [targetNode] : [];
    },

    className: function(nodes, root, className, combinator) {
      if (nodes && combinator) nodes = this[combinator](nodes);
      return Selector.handlers.byClassName(nodes, root, className);
    },

    byClassName: function(nodes, root, className) {
      if (!nodes) nodes = Selector.handlers.descendant([root]);
      var needle = ' ' + className + ' ';
      for (var i = 0, results = [], node, nodeClassName; node = nodes[i]; i++) {
        nodeClassName = node.className;
        if (nodeClassName.length == 0) continue;
        if (nodeClassName == className || (' ' + nodeClassName + ' ').include(needle))
          results.push(node);
      }
      return results;
    },

    attrPresence: function(nodes, root, attr) {
      var results = [];
      for (var i = 0, node; node = nodes[i]; i++)
        if (Element.hasAttribute(node, attr)) results.push(node);
      return results;
    },

    attr: function(nodes, root, attr, value, operator) {
      if (!nodes) nodes = root.getElementsByTagName("*");
      var handler = Selector.operators[operator], results = [];
      for (var i = 0, node; node = nodes[i]; i++) {
        var nodeValue = Element.readAttribute(node, attr);
        if (nodeValue === null) continue;
        if (handler(nodeValue, value)) results.push(node);
      }
      return results;
    },

    pseudo: function(nodes, name, value, root, combinator) {
      if (nodes && combinator) nodes = this[combinator](nodes);
      if (!nodes) nodes = root.getElementsByTagName("*");
      return Selector.pseudos[name](nodes, value, root);
    }
  },

  pseudos: {
    'first-child': function(nodes, value, root) {
      for (var i = 0, results = [], node; node = nodes[i]; i++) {
        if (Selector.handlers.previousElementSibling(node)) continue;
          results.push(node);
      }
      return results;
    },
    'last-child': function(nodes, value, root) {
      for (var i = 0, results = [], node; node = nodes[i]; i++) {
        if (Selector.handlers.nextElementSibling(node)) continue;
          results.push(node);
      }
      return results;
    },
    'only-child': function(nodes, value, root) {
      var h = Selector.handlers;
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        if (!h.previousElementSibling(node) && !h.nextElementSibling(node))
          results.push(node);
      return results;
    },
    'nth-child':        function(nodes, formula, root) {
      return Selector.pseudos.nth(nodes, formula, root);
    },
    'nth-last-child':   function(nodes, formula, root) {
      return Selector.pseudos.nth(nodes, formula, root, true);
    },
    'nth-of-type':      function(nodes, formula, root) {
      return Selector.pseudos.nth(nodes, formula, root, false, true);
    },
    'nth-last-of-type': function(nodes, formula, root) {
      return Selector.pseudos.nth(nodes, formula, root, true, true);
    },
    'first-of-type':    function(nodes, formula, root) {
      return Selector.pseudos.nth(nodes, "1", root, false, true);
    },
    'last-of-type':     function(nodes, formula, root) {
      return Selector.pseudos.nth(nodes, "1", root, true, true);
    },
    'only-of-type':     function(nodes, formula, root) {
      var p = Selector.pseudos;
      return p['last-of-type'](p['first-of-type'](nodes, formula, root), formula, root);
    },

    // handles the an+b logic
    getIndices: function(a, b, total) {
      if (a == 0) return b > 0 ? [b] : [];
      return $R(1, total).inject([], function(memo, i) {
        if (0 == (i - b) % a && (i - b) / a >= 0) memo.push(i);
        return memo;
      });
    },

    // handles nth(-last)-child, nth(-last)-of-type, and (first|last)-of-type
    nth: function(nodes, formula, root, reverse, ofType) {
      if (nodes.length == 0) return [];
      if (formula == 'even') formula = '2n+0';
      if (formula == 'odd')  formula = '2n+1';
      var h = Selector.handlers, results = [], indexed = [], m;
      h.mark(nodes);
      for (var i = 0, node; node = nodes[i]; i++) {
        if (!node.parentNode._counted) {
          h.index(node.parentNode, reverse, ofType);
          indexed.push(node.parentNode);
        }
      }
      if (formula.match(/^\d+$/)) { // just a number
        formula = Number(formula);
        for (var i = 0, node; node = nodes[i]; i++)
          if (node.nodeIndex == formula) results.push(node);
      } else if (m = formula.match(/^(-?\d*)?n(([+-])(\d+))?/)) { // an+b
        if (m[1] == "-") m[1] = -1;
        var a = m[1] ? Number(m[1]) : 1;
        var b = m[2] ? Number(m[2]) : 0;
        var indices = Selector.pseudos.getIndices(a, b, nodes.length);
        for (var i = 0, node, l = indices.length; node = nodes[i]; i++) {
          for (var j = 0; j < l; j++)
            if (node.nodeIndex == indices[j]) results.push(node);
        }
      }
      h.unmark(nodes);
      h.unmark(indexed);
      return results;
    },

    'empty': function(nodes, value, root) {
      for (var i = 0, results = [], node; node = nodes[i]; i++) {
        // IE treats comments as element nodes
        if (node.tagName == '!' || (node.firstChild && !node.innerHTML.match(/^\s*$/))) continue;
        results.push(node);
      }
      return results;
    },

    'not': function(nodes, selector, root) {
      var h = Selector.handlers, selectorType, m;
      var exclusions = new Selector(selector).findElements(root);
      h.mark(exclusions);
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        if (!node._counted) results.push(node);
      h.unmark(exclusions);
      return results;
    },

    'enabled': function(nodes, value, root) {
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        if (!node.disabled) results.push(node);
      return results;
    },

    'disabled': function(nodes, value, root) {
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        if (node.disabled) results.push(node);
      return results;
    },

    'checked': function(nodes, value, root) {
      for (var i = 0, results = [], node; node = nodes[i]; i++)
        if (node.checked) results.push(node);
      return results;
    }
  },

  operators: {
    '=':  function(nv, v) { return nv == v; },
    '!=': function(nv, v) { return nv != v; },
    '^=': function(nv, v) { return nv.startsWith(v); },
    '$=': function(nv, v) { return nv.endsWith(v); },
    '*=': function(nv, v) { return nv.include(v); },
    '~=': function(nv, v) { return (' ' + nv + ' ').include(' ' + v + ' '); },
    '|=': function(nv, v) { return ('-' + nv.toUpperCase() + '-').include('-' + v.toUpperCase() + '-'); }
  },

  matchElements: function(elements, expression) {
    var matches = new Selector(expression).findElements(), h = Selector.handlers;
    h.mark(matches);
    for (var i = 0, results = [], element; element = elements[i]; i++)
      if (element._counted) results.push(element);
    h.unmark(matches);
    return results;
  },

  findElement: function(elements, expression, index) {
    if (typeof expression == 'number') {
      index = expression; expression = false;
    }
    return Selector.matchElements(elements, expression || '*')[index || 0];
  },

  findChildElements: function(element, expressions) {
    var exprs = expressions.join(','), expressions = [];
    exprs.scan(/(([\w#:.~>+()\s-]+|\*|\[.*?\])+)\s*(,|$)/, function(m) {
      expressions.push(m[1].strip());
    });
    var results = [], h = Selector.handlers;
    for (var i = 0, l = expressions.length, selector; i < l; i++) {
      selector = new Selector(expressions[i].strip());
      h.concat(results, selector.findElements(element));
    }
    return (l > 1) ? h.unique(results) : results;
  }
});

function $$() {
  return Selector.findChildElements(document, $A(arguments));
}
var Form = {
  reset: function(form) {
    $(form).reset();
    return form;
  },

  serializeElements: function(elements, getHash) {
    var data = elements.inject({}, function(result, element) {
      if (!element.disabled && element.name) {
        var key = element.name, value = $(element).getValue();
        if (value != null) {
         	if (key in result) {
            if (result[key].constructor != Array) result[key] = [result[key]];
            result[key].push(value);
          }
          else result[key] = value;
        }
      }
      return result;
    });

    return getHash ? data : Hash.toQueryString(data);
  }
};

Form.Methods = {
  serialize: function(form, getHash) {
    return Form.serializeElements(Form.getElements(form), getHash);
  },

  getElements: function(form) {
    return $A($(form).getElementsByTagName('*')).inject([],
      function(elements, child) {
        if (Form.Element.Serializers[child.tagName.toLowerCase()])
          elements.push(Element.extend(child));
        return elements;
      }
    );
  },

  getInputs: function(form, typeName, name) {
    form = $(form);
    var inputs = form.getElementsByTagName('input');

    if (!typeName && !name) return $A(inputs).map(Element.extend);

    for (var i = 0, matchingInputs = [], length = inputs.length; i < length; i++) {
      var input = inputs[i];
      if ((typeName && input.type != typeName) || (name && input.name != name))
        continue;
      matchingInputs.push(Element.extend(input));
    }

    return matchingInputs;
  },

  disable: function(form) {
    form = $(form);
    Form.getElements(form).invoke('disable');
    return form;
  },

  enable: function(form) {
    form = $(form);
    Form.getElements(form).invoke('enable');
    return form;
  },

  findFirstElement: function(form) {
    return $(form).getElements().find(function(element) {
      return element.type != 'hidden' && !element.disabled &&
        ['input', 'select', 'textarea'].include(element.tagName.toLowerCase());
    });
  },

  focusFirstElement: function(form) {
    form = $(form);
    form.findFirstElement().activate();
    return form;
  },

  request: function(form, options) {
    form = $(form), options = Object.clone(options || {});

    var params = options.parameters;
    options.parameters = form.serialize(true);

    if (params) {
      if (typeof params == 'string') params = params.toQueryParams();
      Object.extend(options.parameters, params);
    }

    if (form.hasAttribute('method') && !options.method)
      options.method = form.method;

    return new Ajax.Request(form.readAttribute('action'), options);
  }
}

/*--------------------------------------------------------------------------*/

Form.Element = {
  focus: function(element) {
    $(element).focus();
    return element;
  },

  select: function(element) {
    $(element).select();
    return element;
  }
}

Form.Element.Methods = {
  serialize: function(element) {
    element = $(element);
    if (!element.disabled && element.name) {
      var value = element.getValue();
      if (value != undefined) {
        var pair = {};
        pair[element.name] = value;
        return Hash.toQueryString(pair);
      }
    }
    return '';
  },

  getValue: function(element) {
    element = $(element);
    var method = element.tagName.toLowerCase();
    return Form.Element.Serializers[method](element);
  },

  clear: function(element) {
    $(element).value = '';
    return element;
  },

  present: function(element) {
    return $(element).value != '';
  },

  activate: function(element) {
    element = $(element);
    try {
      element.focus();
      if (element.select && (element.tagName.toLowerCase() != 'input' ||
        !['button', 'reset', 'submit'].include(element.type)))
        element.select();
    } catch (e) {}
    return element;
  },

  disable: function(element) {
    element = $(element);
    element.blur();
    element.disabled = true;
    return element;
  },

  enable: function(element) {
    element = $(element);
    element.disabled = false;
    return element;
  }
}

/*--------------------------------------------------------------------------*/

var Field = Form.Element;
var $F = Form.Element.Methods.getValue;

/*--------------------------------------------------------------------------*/

Form.Element.Serializers = {
  input: function(element) {
    switch (element.type.toLowerCase()) {
      case 'checkbox':
      case 'radio':
        return Form.Element.Serializers.inputSelector(element);
      default:
        return Form.Element.Serializers.textarea(element);
    }
  },

  inputSelector: function(element) {
    return element.checked ? element.value : null;
  },

  textarea: function(element) {
    return element.value;
  },

  select: function(element) {
    return this[element.type == 'select-one' ?
      'selectOne' : 'selectMany'](element);
  },

  selectOne: function(element) {
    var index = element.selectedIndex;
    return index >= 0 ? this.optionValue(element.options[index]) : null;
  },

  selectMany: function(element) {
    var values, length = element.length;
    if (!length) return null;

    for (var i = 0, values = []; i < length; i++) {
      var opt = element.options[i];
      if (opt.selected) values.push(this.optionValue(opt));
    }
    return values;
  },

  optionValue: function(opt) {
    // extend element because hasAttribute may not be native
    return Element.extend(opt).hasAttribute('value') ? opt.value : opt.text;
  }
}

/*--------------------------------------------------------------------------*/

Abstract.TimedObserver = function() {}
Abstract.TimedObserver.prototype = {
  initialize: function(element, frequency, callback) {
    this.frequency = frequency;
    this.element   = $(element);
    this.callback  = callback;

    this.lastValue = this.getValue();
    this.registerCallback();
  },

  registerCallback: function() {
    setInterval(this.onTimerEvent.bind(this), this.frequency * 1000);
  },

  onTimerEvent: function() {
    var value = this.getValue();
    var changed = ('string' == typeof this.lastValue && 'string' == typeof value
      ? this.lastValue != value : String(this.lastValue) != String(value));
    if (changed) {
      this.callback(this.element, value);
      this.lastValue = value;
    }
  }
}

Form.Element.Observer = Class.create();
Form.Element.Observer.prototype = Object.extend(new Abstract.TimedObserver(), {
  getValue: function() {
    return Form.Element.getValue(this.element);
  }
});

Form.Observer = Class.create();
Form.Observer.prototype = Object.extend(new Abstract.TimedObserver(), {
  getValue: function() {
    return Form.serialize(this.element);
  }
});

/*--------------------------------------------------------------------------*/

Abstract.EventObserver = function() {}
Abstract.EventObserver.prototype = {
  initialize: function(element, callback) {
    this.element  = $(element);
    this.callback = callback;

    this.lastValue = this.getValue();
    if (this.element.tagName.toLowerCase() == 'form')
      this.registerFormCallbacks();
    else
      this.registerCallback(this.element);
  },

  onElementEvent: function() {
    var value = this.getValue();
    if (this.lastValue != value) {
      this.callback(this.element, value);
      this.lastValue = value;
    }
  },

  registerFormCallbacks: function() {
    Form.getElements(this.element).each(this.registerCallback.bind(this));
  },

  registerCallback: function(element) {
    if (element.type) {
      switch (element.type.toLowerCase()) {
        case 'checkbox':
        case 'radio':
          Event.observe(element, 'click', this.onElementEvent.bind(this));
          break;
        default:
          Event.observe(element, 'change', this.onElementEvent.bind(this));
          break;
      }
    }
  }
}

Form.Element.EventObserver = Class.create();
Form.Element.EventObserver.prototype = Object.extend(new Abstract.EventObserver(), {
  getValue: function() {
    return Form.Element.getValue(this.element);
  }
});

Form.EventObserver = Class.create();
Form.EventObserver.prototype = Object.extend(new Abstract.EventObserver(), {
  getValue: function() {
    return Form.serialize(this.element);
  }
});
if (!window.Event) {
  var Event = new Object();
}

Object.extend(Event, {
  KEY_BACKSPACE: 8,
  KEY_TAB:       9,
  KEY_RETURN:   13,
  KEY_ESC:      27,
  KEY_LEFT:     37,
  KEY_UP:       38,
  KEY_RIGHT:    39,
  KEY_DOWN:     40,
  KEY_DELETE:   46,
  KEY_HOME:     36,
  KEY_END:      35,
  KEY_PAGEUP:   33,
  KEY_PAGEDOWN: 34,

  element: function(event) {
    return $(event.target || event.srcElement);
  },

  isLeftClick: function(event) {
    return (((event.which) && (event.which == 1)) ||
            ((event.button) && (event.button == 1)));
  },

  pointerX: function(event) {
    return event.pageX || (event.clientX +
      (document.documentElement.scrollLeft || document.body.scrollLeft));
  },

  pointerY: function(event) {
    return event.pageY || (event.clientY +
      (document.documentElement.scrollTop || document.body.scrollTop));
  },

  stop: function(event) {
    if (event.preventDefault) {
      event.preventDefault();
      event.stopPropagation();
    } else {
      event.returnValue = false;
      event.cancelBubble = true;
    }
  },

  // find the first node with the given tagName, starting from the
  // node the event was triggered on; traverses the DOM upwards
  findElement: function(event, tagName) {
    var element = Event.element(event);
    while (element.parentNode && (!element.tagName ||
        (element.tagName.toUpperCase() != tagName.toUpperCase())))
      element = element.parentNode;
    return element;
  },

  observers: false,

  _observeAndCache: function(element, name, observer, useCapture) {
    if (!this.observers) this.observers = [];
    if (element.addEventListener) {
      this.observers.push([element, name, observer, useCapture]);
      element.addEventListener(name, observer, useCapture);
    } else if (element.attachEvent) {
      this.observers.push([element, name, observer, useCapture]);
      element.attachEvent('on' + name, observer);
    }
  },

  unloadCache: function() {
    if (!Event.observers) return;
    for (var i = 0, length = Event.observers.length; i < length; i++) {
      Event.stopObserving.apply(this, Event.observers[i]);
      Event.observers[i][0] = null;
    }
    Event.observers = false;
  },

  observe: function(element, name, observer, useCapture) {
    element = $(element);
    useCapture = useCapture || false;

    if (name == 'keypress' &&
      (Prototype.Browser.WebKit || element.attachEvent))
      name = 'keydown';

    Event._observeAndCache(element, name, observer, useCapture);
  },

  stopObserving: function(element, name, observer, useCapture) {
    element = $(element);
    useCapture = useCapture || false;

    if (name == 'keypress' &&
        (Prototype.Browser.WebKit || element.attachEvent))
      name = 'keydown';

    if (element.removeEventListener) {
      element.removeEventListener(name, observer, useCapture);
    } else if (element.detachEvent) {
      try {
        element.detachEvent('on' + name, observer);
      } catch (e) {}
    }
  }
});

/* prevent memory leaks in IE */
if (Prototype.Browser.IE)
  Event.observe(window, 'unload', Event.unloadCache, false);
var Position = {
  // set to true if needed, warning: firefox performance problems
  // NOT neeeded for page scrolling, only if draggable contained in
  // scrollable elements
  includeScrollOffsets: false,

  // must be called before calling withinIncludingScrolloffset, every time the
  // page is scrolled
  prepare: function() {
    this.deltaX =  window.pageXOffset
                || document.documentElement.scrollLeft
                || document.body.scrollLeft
                || 0;
    this.deltaY =  window.pageYOffset
                || document.documentElement.scrollTop
                || document.body.scrollTop
                || 0;
  },

  realOffset: function(element) {
    var valueT = 0, valueL = 0;
    do {
      valueT += element.scrollTop  || 0;
      valueL += element.scrollLeft || 0;
      element = element.parentNode;
    } while (element);
    return [valueL, valueT];
  },

  cumulativeOffset: function(element) {
    var valueT = 0, valueL = 0;
    do {
      valueT += element.offsetTop  || 0;
      valueL += element.offsetLeft || 0;
      element = element.offsetParent;
    } while (element);
    return [valueL, valueT];
  },

  positionedOffset: function(element) {
    var valueT = 0, valueL = 0;
    do {
      valueT += element.offsetTop  || 0;
      valueL += element.offsetLeft || 0;
      element = element.offsetParent;
      if (element) {
        if(element.tagName=='BODY') break;
        var p = Element.getStyle(element, 'position');
        if (p == 'relative' || p == 'absolute') break;
      }
    } while (element);
    return [valueL, valueT];
  },

  offsetParent: function(element) {
    if (element.offsetParent) return element.offsetParent;
    if (element == document.body) return element;

    while ((element = element.parentNode) && element != document.body)
      if (Element.getStyle(element, 'position') != 'static')
        return element;

    return document.body;
  },

  // caches x/y coordinate pair to use with overlap
  within: function(element, x, y) {
    if (this.includeScrollOffsets)
      return this.withinIncludingScrolloffsets(element, x, y);
    this.xcomp = x;
    this.ycomp = y;
    this.offset = this.cumulativeOffset(element);

    return (y >= this.offset[1] &&
            y <  this.offset[1] + element.offsetHeight &&
            x >= this.offset[0] &&
            x <  this.offset[0] + element.offsetWidth);
  },

  withinIncludingScrolloffsets: function(element, x, y) {
    var offsetcache = this.realOffset(element);

    this.xcomp = x + offsetcache[0] - this.deltaX;
    this.ycomp = y + offsetcache[1] - this.deltaY;
    this.offset = this.cumulativeOffset(element);

    return (this.ycomp >= this.offset[1] &&
            this.ycomp <  this.offset[1] + element.offsetHeight &&
            this.xcomp >= this.offset[0] &&
            this.xcomp <  this.offset[0] + element.offsetWidth);
  },

  // within must be called directly before
  overlap: function(mode, element) {
    if (!mode) return 0;
    if (mode == 'vertical')
      return ((this.offset[1] + element.offsetHeight) - this.ycomp) /
        element.offsetHeight;
    if (mode == 'horizontal')
      return ((this.offset[0] + element.offsetWidth) - this.xcomp) /
        element.offsetWidth;
  },

  page: function(forElement) {
    var valueT = 0, valueL = 0;

    var element = forElement;
    do {
      valueT += element.offsetTop  || 0;
      valueL += element.offsetLeft || 0;

      // Safari fix
      if (element.offsetParent == document.body)
        if (Element.getStyle(element,'position')=='absolute') break;

    } while (element = element.offsetParent);

    element = forElement;
    do {
      if (!window.opera || element.tagName=='BODY') {
        valueT -= element.scrollTop  || 0;
        valueL -= element.scrollLeft || 0;
      }
    } while (element = element.parentNode);

    return [valueL, valueT];
  },

  clone: function(source, target) {
    var options = Object.extend({
      setLeft:    true,
      setTop:     true,
      setWidth:   true,
      setHeight:  true,
      offsetTop:  0,
      offsetLeft: 0
    }, arguments[2] || {})

    // find page position of source
    source = $(source);
    var p = Position.page(source);

    // find coordinate system to use
    target = $(target);
    var delta = [0, 0];
    var parent = null;
    // delta [0,0] will do fine with position: fixed elements,
    // position:absolute needs offsetParent deltas
    if (Element.getStyle(target,'position') == 'absolute') {
      parent = Position.offsetParent(target);
      delta = Position.page(parent);
    }

    // correct by body offsets (fixes Safari)
    if (parent == document.body) {
      delta[0] -= document.body.offsetLeft;
      delta[1] -= document.body.offsetTop;
    }

    // set position
    if(options.setLeft)   target.style.left  = (p[0] - delta[0] + options.offsetLeft) + 'px';
    if(options.setTop)    target.style.top   = (p[1] - delta[1] + options.offsetTop) + 'px';
    if(options.setWidth)  target.style.width = source.offsetWidth + 'px';
    if(options.setHeight) target.style.height = source.offsetHeight + 'px';
  },

  absolutize: function(element) {
    element = $(element);
    if (element.style.position == 'absolute') return;
    Position.prepare();

    var offsets = Position.positionedOffset(element);
    var top     = offsets[1];
    var left    = offsets[0];
    var width   = element.clientWidth;
    var height  = element.clientHeight;

    element._originalLeft   = left - parseFloat(element.style.left  || 0);
    element._originalTop    = top  - parseFloat(element.style.top || 0);
    element._originalWidth  = element.style.width;
    element._originalHeight = element.style.height;

    element.style.position = 'absolute';
    element.style.top    = top + 'px';
    element.style.left   = left + 'px';
    element.style.width  = width + 'px';
    element.style.height = height + 'px';
  },

  relativize: function(element) {
    element = $(element);
    if (element.style.position == 'relative') return;
    Position.prepare();

    element.style.position = 'relative';
    var top  = parseFloat(element.style.top  || 0) - (element._originalTop || 0);
    var left = parseFloat(element.style.left || 0) - (element._originalLeft || 0);

    element.style.top    = top + 'px';
    element.style.left   = left + 'px';
    element.style.height = element._originalHeight;
    element.style.width  = element._originalWidth;
  }
}

// Safari returns margins on body which is incorrect if the child is absolutely
// positioned.  For performance reasons, redefine Position.cumulativeOffset for
// KHTML/WebKit only.
if (Prototype.Browser.WebKit) {
  Position.cumulativeOffset = function(element) {
    var valueT = 0, valueL = 0;
    do {
      valueT += element.offsetTop  || 0;
      valueL += element.offsetLeft || 0;
      if (element.offsetParent == document.body)
        if (Element.getStyle(element, 'position') == 'absolute') break;

      element = element.offsetParent;
    } while (element);

    return [valueL, valueT];
  }
}

Element.addMethods();