一段防止闭包的javascript代码

<script>

var test={};

test.doo=function(i){

alert("时间到了，我要做点事情。"+i);

};

Function.prototype.createCallback=function(){

 var that=this;

var args=[].slice.apply(arguments);

return function(){ that.apply(null,args);

};

 };

window.onload=function(){

 var memory="";

var i=1;

for(i=0;i<10000;i++) memory+="eat memory";

setTimeout (test.doo.createCallback(i),50000);

}

</script>