list[i].i=i;的位置问题

        for(var i=0;i<list.length;i++){
          list[i].i=i
          list[i].onmouseover=function(){
            this.className="lihover";
            var h0=(this.i)*30+42;
            var y=this.getElementsByTagName("div")[0].offsetHeight;
            var h=this.getElementsByTagName("div")[0].style.top+y;
            if(h<h0){
              this.getElementsByTagName("div")[0].style.top=h0+"px";
            }
          };
          list[i].onmouseout=function(){
            this.className="";
          };
        }

为什么当list[i].i=i;放在onmouseover事件内部没有效果?