manage javascript dependancies

JSRequire.js

/*
    JSRequire module
    by: wangyu (bigeyex@gmail.com)
    manage javascript dependancies.
    usage: 
        jsrequire(['one.js', 'two.js'], function(){
            // code after one.js and two.js loaded...
        });
*/
function JSRequire(base_path){
    this.scriptList = {};
    this.waitingList = [];
    this.waitingCallbacks = [];
    this.basePath = base_path?base_path:'';
    var self = this;

    window.jsrequire = function(scripts, callback){
        var needLoad = false;
        for(var i in scripts){
            if(!(scripts[i] in self.scriptList)){
                needLoad = true;
                self.waitingList.push(scripts[i]);
            }
        }
        if(needLoad){
            self.waitingCallbacks.push(callback);
            self.loadScript();
        }
        else{
            callback();
        }
    };

    this.loadScript = function(){
        var oneScript = self.waitingList.pop();
        if(oneScript){
            var head= document.getElementsByTagName('head')[0];
            var script= document.createElement('script');
            script.type= 'text/javascript';
            script.onreadystatechange= function () {
               if (this.readyState == 'loaded' || this.readyState == 'complete') self.scriptLoaded();
            }
            script.onload= self.scriptLoaded;
            script.src= self.basePath+oneScript;
            head.appendChild(script);
        }
    };

    this.scriptLoaded = function(){
        if(self.waitingList.length > 0){
            self.loadScript();
        }
        else{
            for(var i in self.waitingCallbacks){
                self.waitingCallbacks[i]();
            }
        }
    };
}
new JSRequire(app_path+'/Public/js/');