var JSLoader = function(){
	
	var scripts = {}; // scripts['a.js'] = {loaded:false,funs:[]}
	
	function getScript(url){
		var script = scripts[url];
		if (!script){
			script = {loaded:false, funs:[]};
			scripts[url] = script;
			add(script, url);
		}
		return script;
	}
	
				
	function run(script){
		var funs = script.funs,
			len = funs.length,
			i = 0;
		
		for (; i<len; i++){
			var fun = funs.pop();
			fun();
		}
	}
	
	function add(script, url){
		var scriptdom = document.createElement('script');
		scriptdom.type = 'text/javascript';
		scriptdom.loaded = false;
		scriptdom.src = url;
		
		scriptdom.onload = function(){
			scriptdom.loaded = true;
			run(script);
			scriptdom.onload = scriptdom.onreadystatechange = null;
		};
		
		//for ie
		scriptdom.onreadystatechange = function(){
			if ((scriptdom.readyState === 'loaded' || 
					scriptdom.readyState === 'complete') && !scriptdom.loaded) {
				
				run(script);
				scriptdom.onload = scriptdom.onreadystatechange = null;
			}
		};
		
		document.getElementsByTagName('head')[0].appendChild(scriptdom);
	}
	
	return {
		load: function(url){
			var arg = arguments,
				len = arg.length,
				i = 1,
				script = getScript(url),
				loaded = script.loaded;
			
			for (; i<len; i++){
				var fun = arg[i];
				if (typeof fun === 'function'){
					if (loaded) {
						fun();
					}else{
						script.funs.push(fun);
					}
				}
			}
		}
	};
}();