var id = 0;

 function JSONP(url,param,cb){

     var callbackName = "json_" + id++;

     var arg = Array.prototype.slice.call(arguments);

     var _cb = arg.pop();

     window[callbackName] = function(data){

         head.removeChild(scriptNode);

         window[callbackName] = null;

         if(typeof _cb == "function"){

             _cb(data);

         }

     }

     var _url = url.replace("callback=?","callback="+callbackName);

     if(param){

         var arr = [];

         for(i in param){

             arr.push(i+"="+arr[i]);

         }

         _url += "&"+arr.join("&");

     }

     var head  =document.getElementsByTagName("head")[0];

     var scriptNode = document.createElement("script");

     scriptNode.src = _url;

     head.appendChild(scriptNode);

 }

 function EventMachine(){

     var _o  = {};

     this.bind = function(e,cb){

         if(!_o[e]){

             _o[e] = [];

         }

         _o[e].push(cb);

     }

     this.trigger = function(e,param){

         if(arguments.length==2&&Object.prototype.toString.call(param) == "[object Array]"){

             var arg = param;

         }else{

             var arg = Array.prototype.slice.call(arguments,1);

         }

         if(_o[e]&&_o[e].length>0){

             for(var i=0,l=_o[e].length;i<l;i++){

                 _o[e][i].apply(this,arg);

             }

         }

     }

 }