用Jquery写返回顶部代码
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>jquery动态回到顶部特效</title>
</head>
<body>
<style>
.up {position: fixed;bottom:35px;right:35px;cursor:pointer;display:none;}
</style>
<p>Just do what you want do!!!</p>
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<div class="up">↑</div>
<script type="text/javascript" src="http://cdn.static.runoob.com/libs/jquery/2.1.1/jquery.min.js"></script>
<script type="text/javascript">
var fh=$('.up');
$(document).scroll(function() {
var gdt=$(window).scrollTop();
if(gdt>=200){
fh.css('display','block')
}else{
fh.css('display','none')
}
});
fh.click(function(){
var c=$(window).scrollTop();
if(c>0){
timg=setInterval(function(){
$(window).scrollTop(c);
if(c>0){
c-=10
}else{
clearInterval(timg)
}
},0.5)
}
});
</script>
</body>
</html>
