//判断函数行参长度来决定是否需要重写setTimeout，ie8以下为undefined

 if(window.setTimeout.length == undefined){

     var __sto = window.setTimeout;

     window.setTimeout = function(callback,timeout,param){

         var args = Array.prototype.slice.call(arguments,2);

         __sto(function(){

             callback.apply(null,args);

         },timeout);

     };

 }