jQuery小火箭返回顶部：
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<style>
body {
height: 8000px;
}
a {
color: #FFF;
}
.actGotop {
position: fixed;
bottom: 50px;
right: 50px;
width: 150px;
height: 195px;
display: none;
z-index: 100;
}
.actGotop a, .actGotop a:link {
width: 150px;
height: 195px;
display: inline-block;
background: url(images/gotop.png) no-repeat;
outline: none;
}
.actGotop a:hover {
width: 150px;
height: 195px;
background: url(images/gotop.gif) no-repeat;
outline: none;
}
</style>
</head>
<body>
<!-- 返回顶部小火箭 -->
<div class="actGotop"><a href="javascript:;" title="Top"></a></div>
<script src="jquery-1.12.4.js"></script>
<script>
$(function () {
//当页面超出去1000px的时候，让小火箭显示出来,如果小于1000，就让小火箭隐藏
$(window).scroll(function () {
if($(window).scrollTop() >= 1000 ){
$(".actGotop").stop().fadeIn(1000);
}else {
$(".actGotop").stop().fadeOut(1000);
}
});
//在外面注册
$(".actGotop").click(function () {
$("html,body").stop().animate({scrollTop:0},3000);
});
});
</script>
</body>
</html>