js控制滚动条缓慢滚动到顶部

　2012-12-26 15:17:59　来源：WEB开发网　　　

核心提示：<html><head><script type="text/javascript">var currentPosition,timer;function GoTop(){timer=setInterval("runToTop()",1);}f

<html>
<head>
<script type="text/javascript">
var currentPosition,timer;
function GoTop(){
	timer=setInterval("runToTop()",1);
}
function runToTop(){
	currentPosition=document.documentElement.scrollTop || document.body.scrollTop; 
	currentPosition-=10;
	if(currentPosition>0)
	{
		window.scrollTo(0,currentPosition);
	}
	else
	{
		window.scrollTo(0,0);
		clearInterval(timer);
	}
}
</script>
<style type="text/css">

</style>
</head>
<body>
<div style="height:1000px;text-align:center;font-size:200px;font-weight:bold;">饭</div>
<div style="height:1000px;text-align:center;font-size:200px;font-weight:bold;">吃</div>
<div style="height:1000px;text-align:center;font-size:200px;font-weight:bold;">家</div>
<div style="height:1000px;text-align:center;font-size:200px;font-weight:bold;">回</div>
<div style="height:1000px;text-align:center;font-size:200px;font-weight:bold;">你</div>
<div style="height:1000px;text-align:center;font-size:200px;font-weight:bold;">带</div>
<div id="back-up" onclick="GoTop()" style="border:1px solid red;height:100px;width:15px;position:fixed;cursor:pointer;right:10px;bottom:30px;">返回顶部</div>
<script>
window.scrollTo(0,document.body.scrollHeight);
</script>
</body>
</html>