jQuery实现返回顶部功能_jquery

HTML：

 
 
 去顶部
 
 

CSS：

 .fl{
 display:block;
 float:left;
 width:50px;
 height:50px;
 text-align:center;
 background-color:#eaeaea;
 background-image:url(../images/toTop.png);
 }
 .fl:hover{background-color:#f442;background-image:url(../images/toTop.png);}

 #Fixed {
 position: fixed;
 _position: absolute;
 z-index: 100;
 bottom: 70px;
 left: 50%;
 margin-left: 530px;
 _bottom: auto;_top:
 expression(document.documentElement.scrollTop+document.documentElement.clientHeight-this.offsetHeight-70);
 width: 50px;
 text-indent: -40000px;
 background: #fff
 }

 /*置顶 end*/

Js：