diff --git a/scripts.js b/scripts.js
index ff3739e..661185a 100644
--- a/scripts.js
+++ b/scripts.js
@@ -1,5 +1,5 @@
 
-var book;
+var book
 
 window.onload = function() {
 
@@ -13,13 +13,30 @@ window.onload = function() {
 		"http://dev.justforcomics.com/get/image/?f=comics/extracted/oni_whiteout_melt_1/06.jpg"
 	];
 
-	book = new ComicBook();
-	book.draw("comic", pages);
+	var options = {
+		displayMode: "double",
+		zoomMode: "fitWidth"
+	}
+
+	book = new ComicBook("comic", pages, options);
+	book.draw();
 }
 
-function ComicBook() {
+window.onresize = function() {
+	book.draw();
+}
+
+function ComicBook(id, srcs, opts) {
+
+	this.id = id;
+	this.srcs = srcs;	
+
+	var defaults = {
+		displayMode: "double",	// single / double
+		zoomMode: "fitWidth"	// manual / fitWidth
+	}
+	var options = merge(defaults, opts);
 
-	var srcs = [];
 	var pages = [];
 	var canvas;
 	var context;
@@ -29,25 +46,24 @@ function ComicBook() {
 	var loaded = 0;
 	
 	var scale = 1;
-	var displayMode = "double" // single / double
-	var zoomMode = "fitWidth"; // manual / fitWidth
 
 	/* 
 	 * @param {String} id The canvas ID to draw the comic on.
 	 * @param {Object} srcs An array of all the comic page srcs, in order
 	 * @see #preload
 	 */
-	this.draw = function(id, srcs) {
+	ComicBook.prototype.draw = function() {
 	
 		// setup canvas
-		canvas = document.getElementById(id);
+		canvas = document.getElementById(this.id);
 		context = canvas.getContext("2d");
 
-		// preload images
-		preload(srcs);
-		
+		// preload images if needed
+		if (pages.length != this.srcs.length) this.preload(this.srcs);
+		else this.drawPage();
+
 		// add page controls
-		canvas.addEventListener("click", navigation, false);
+		canvas.addEventListener("click", ComicBook.prototype.navigation, false);
 	}
 
 	/*
@@ -55,10 +71,10 @@ function ComicBook() {
 	 * 
 	 * @param new_scale {Number} Scale the canvas to this ratio
 	 */
-	this.zoom = function(new_scale) {
-		zoomMode = "manual";
+	ComicBook.prototype.zoom = function(new_scale) {
+		options.zoomMode = "manual";
 		scale = new_scale;
-		drawPage();
+		this.drawPage();
 	}
 	
 	/**
@@ -67,7 +83,7 @@ function ComicBook() {
 	 * @param srcs {Object} srcs
 	 * @see #drawPage
 	 */
-	function preload(srcs) {
+	ComicBook.prototype.preload = function(srcs) {
 
 		if (srcs.length < buffer) buffer = srcs.length; // don't get stuck if the buffer level is higher than the number of pages
 
@@ -78,9 +94,8 @@ function ComicBook() {
 			page.src = src;
 			
 			page.onload = function() {
-				
-				pages[i] = this; loaded++;
-				if (loaded == buffer) drawPage();
+				pages[i] = this;loaded++;
+				if (loaded == buffer) ComicBook.prototype.drawPage();
 			}
 		});
 	}
@@ -91,34 +106,30 @@ function ComicBook() {
 	 * TODO: break this down into drawSinglePage() & drawDoublePage()
 	 * TODO: if the current browser doesn't have canvas support, use img tags
 	 */
-	function drawPage() {
-
+	ComicBook.prototype.drawPage = function() {
+	
 		var zoom_scale;
 		var page = pages[pointer];
 		var page2 = pages[pointer + 1];
-		
+
 		if (typeof page != "object") throw "invalid page";
 
 		var width = page.width;
-		var height = page.height;
 		
-		if (displayMode == "double") {
+		if (options.displayMode == "double") {
 
-			// for double page spreads, factor in the width of both pages, set the height to the tallest page
-			if (typeof page2 == "object") {
-				width += page2.width;
-				if (page2.height > page.height) height = page2.height;
-			}
+			// for double page spreads, factor in the width of both pages
+			if (typeof page2 == "object") width += page2.width;
 			
 			// if this is the last page and there is no page2, still keep the canvas wide
 			else width += width;
 		}
-		
+
 		// update the page scale if a non manual mode has been chosen
-		switch(zoomMode) {
+		switch(options.zoomMode) {
 
 			case "manual":
-				zoom_scale = (displayMode == "double") ? scale * 2 : scale;
+				zoom_scale = (options.displayMode == "double") ? scale * 2 : scale;
 				break;
 				
 			case "fitWidth":
@@ -127,22 +138,22 @@ function ComicBook() {
 					  : window.innerWidth / width; // scale down if the window is narrower than the page
 				break;
 				
-			default: throw "invalid zoomMode";
+			default:throw "invalid zoomMode";
 		}
 		
 		var canvas_width  = page.width * zoom_scale;
 		var canvas_height = page.height * zoom_scale;
 
-		var page_width = (zoomMode == "manual") ? page.width * scale : canvas_width;
-		var page_height = (zoomMode == "manual") ? page.height * scale : canvas_height;
+		var page_width = (options.zoomMode == "manual") ? page.width * scale : canvas_width;
+		var page_height = (options.zoomMode == "manual") ? page.height * scale : canvas_height;
 		
 		// make sure the canvas is always at least full screen, even if the page is more narrow than the screen
 		canvas.width = (canvas_width < window.innerWidth) ? window.innerWidth : canvas_width;
 		canvas.height = (canvas_height < window.innerHeight) ? window.innerHeight : canvas_height;
-
+		
 		// draw the page(s)
 		context.drawImage(page, 0, 0, page_width, page_height);
-		if (displayMode == "double" && typeof page2 == "object") context.drawImage(page2, page_width, 0, page_width, page_height);
+		if (options.displayMode == "double" && typeof page2 == "object") context.drawImage(page2, page_width, 0, page_width, page_height);
 		
 	}
 
@@ -151,10 +162,10 @@ function ComicBook() {
 	 * 
 	 * @see #drawPage
 	 */
-	function drawNextPage() {
+	ComicBook.prototype.drawNextPage = function() {
 		if (pointer + 1 < pages.length) {
 			pointer++;
-			drawPage();
+			this.drawPage();
 		}
 	}
 
@@ -163,21 +174,21 @@ function ComicBook() {
 	 *
 	 * @see #drawPage
 	 */
-	function drawPrevPage() {
+	ComicBook.prototype.drawPrevPage = function() {
 		if (pointer > 0) {
 			pointer--;
-			drawPage();
+			this.drawPage();
 		}
 	}
-
-	function navigation(e) {
+	
+	ComicBook.prototype.navigation = function(e) {
 
 		switch (e.type) {
 
 			case "click":
 				switch (getCursorPosition(e)) {
-					case "left": drawPrevPage(); break;
-					case "right": drawNextPage(); break;
+					case "left": ComicBook.prototype.drawPrevPage(); break;
+					case "right": ComicBook.prototype.drawNextPage(); break;
 				}
 				break;
 			
@@ -191,19 +202,38 @@ function ComicBook() {
 	 * Thanks to: Mark Pilgrim & http://diveintohtml5.org/canvas.html
 	 */
 	function getCursorPosition(e) {
-		
+	
 		var x;
 
 		// check if page relative positions exist
 		if (e.pageX) x = e.pageX;
-
+		
 		// if not figure them out
 		else  x = e.clientX + document.body.scrollLeft + document.documentElement.scrollLeft;
-
+		
 		// make the position relative to the canvas
 		x -= canvas.offsetLeft;
-
+		
 		// check if the user clicked on the left or right side
 		return (x <= canvas.width / 2) ? 'left' : 'right';
 	}
-}
+
+	/**
+	 * Merge two arrays. Any properties in b will replace the same properties in
+	 * a. New properties from b will be added to a.
+	 *
+	 * @param a {Object}
+	 * @param b {Object}
+	 */
+	function merge(a, b) {
+	
+		if (typeof b == "undefined") b = {};
+
+		for (prop in a) {
+			if (prop in b) continue;
+			b[prop] = a[prop];
+		}
+		
+		return b;
+	}
+}
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