/**
 * Script lazy loader 0.5 Copyright (c) 2008 Bob Matsuoka
 * 
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License as published by the Free Software
 * Foundation; either version 2 of the License, or (at your option) any later
 * version.
 */

var LazyLoader = {}; // namespace
LazyLoader.timer = {}; // contains timers for scripts
LazyLoader.scripts = []; // contains called script references
LazyLoader.load = function(url, callback) {
	// handle object or path
	var classname = null;
	var properties = null;
	try {
		// make sure we only load once
		if ($A(LazyLoader.scripts).indexOf(url) == -1) {
			// note that we loaded already
			LazyLoader.scripts.push(url);
			var script = document.createElement("script");
			script.src = url;
			script.type = "text/javascript";
			$$("head")[0].appendChild(script); // add script tag to head
			// element

			// was a callback requested
			if (callback) {
				// test for onreadystatechange to trigger callback
				script.onreadystatechange = function() {
					if (script.readyState == 'loaded'
							|| script.readyState == 'complete') {
						callback();
					}
				}
				// test for onload to trigger callback
				script.onload = function() {
					callback();
					return;
				}
				// safari doesn't support either onload or readystate, create a
				// timer
				// only way to do this in safari
				if ((Prototype.Browser.WebKit && !navigator.userAgent
						.match(/Version\/3/))
						|| Prototype.Browser.Opera) { // sniff
					LazyLoader.timer[url] = setInterval( function() {
						if (/loaded|complete/.test(document.readyState)) {
							clearInterval(LazyLoader.timer[url]);
							callback(); // call the callback handler
						}
					}, 10);
				}
			}
		} else {
			if (callback) {
				callback();
			}
		}
	} catch (e) {
		alert(e);
	}
}
/**
 * 1. LazyLoader.load('js/myscript2.js', function(){ var myobj = new
 * MyObject('myobj'); });
 * 
 * 2. LazyLoader.load('js/myscript1.js');
 * 
 * 
 */