//随页面滚动的div
   function scrollDiv(e){
       var scrollTop=window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop || 0;
       var top=parseInt(e.style.top);
       if(scrollTop!=top){
           e.style.top=scrollTop+'px'
       }
       //以下是如何给setTimeout传递参数的方法(js遇到无法传参时都可考虑用此方法)
       var func=function(div){return function(){scrollDiv(div)}}(e);
       window.setTimeout(func,300);
   }   
   window.onload=function(){
       scrollDiv(document.getElementById('msn'));
   }