又一款返回顶部图标代码

把代码添加到第三方：

[CSS] 纯文本查看 复制代码

<style>
#pam {
        position: fixed;
        display: none;
        bottom: 4px;
        height: 53px;
        right: 4px;
        width: 53px;
        _position: absolute;
        _top: expression(eval(document.documentElement.scrollTop+document.documentElement.clientHeight-this.offsetHeight-(parseInt(this.currentStyle.marginTop,10)||0)-(parseInt(this.currentStyle.marginBottom,10)||0)));
}
#pam .top_img {
        display: block;
        height: 50px;
        width: 50px;
        background: url("https://boonkiong.com/b/p/top.png") no-repeat;
}
#pam .top_img:hover {
        background-position: center bottom;
}

</style>
<div id="pam" style="display: block;"><a class="top_img" href="#"></a></div>

<script language="javascript"
type="text/javascript">
function
getScroll(id){
var obj =
document.getElementById(id);
var timer =
null;
positionFixed(obj);

if(obj){
  obj.style.display =
'none';
  
window.onscroll=function(){
  
getScrollTop() > 0 ? obj.style.display = "block" :
obj.style.display = "none";
  
}
  
obj.onclick=function(){
  
var timer = setInterval(sMove,10);

  function sMove(){

   
setScrollTop(getScrollTop() / 1.5);
  
  if(getScrollTop() <
1)clearInterval(timer);
  
}
  
}
}
}
//判断IE6
function
positionFixed(obj){
var iE6 = !-[1,] &&
!window.XMLHttpRequest;
if(obj){


}
}
//获取滚动条Top
function
getScrollTop(){
return document.documentElement.scrollTop
|| document.body.scrollTop;
}
//回到顶部
function
setScrollTop(value){
document.documentElement.scrollTop =
value;
document.body.scrollTop =
value;
}
window.onload = function(){

getScroll('pam');
};
</script>