<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>点击回到页面顶部</title>
<style type="text/css">
*{margin: 0;padding: 0;}
.scroll_top{60px;height: 60px;border: 1px solid red;position: fixed;bottom: 50px;right: 20px;display: none;}
.scroll_top span{ 60px;height:60px ;display: block;background: url(img/icon_top.png) no-repeat center #20B2AA;border-radius:30px ;}
</style>
</head>
<body>
<pre>
<img src="img/qq.png" />
</pre>
<div class="scroll_top">
<span id="s_btn"></span>
</div>
<script type="text/javascript" src="js/jquery.js" ></script>
<script type="text/javascript">
$("#s_btn").click(function(){
$("html,body").animate({
scrollTop:0
},100);
});
$(window).scroll(function(){
if ($(this).scrollTop() >= 300) {
$(".scroll_top").fadeIn(300);
} else{
$(".scroll_top").stop(true,true).fadeOut(100);
}
});
</script>
</body>
</html>