鼠標移動上去，彈出一個div，並且div跟隨鼠標移動。
代碼如下：
<!DOCTYPE html>
<html lang="zh-cn">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<script src="http://libs.baidu.com/jquery/2.0.0/jquery.min.js"></script>
<style>
body{width:960px;margin:0 auto;}
ul{list-style:none;width:960px;height:300px;margin-top:100px;}
.a{background-color:#0f0;width:200px;height:200px;float:left;margin:20px;}
.b{background-color:#00f;width:300px;height:300px;display:none;position: absolute;color: #fff;font-size: 120px;}
</style>
</head>
<body>
<ul class="list">
<li><div class="a">1</div></li>
<li><div class="a">2</div></li>
<li><div class="a">3</div></li>
</ul>
<div class="b">1-1</div>
<div class="b">2-2</div>
<div class="b">3-3</div>
<script type="text/javascript">
$('.b').hide();
$('.list li').mousemove(function(e){
$('.b').eq($(this).index()).show().css({
"top": e.pageY+20,
"left": e.pageX+20
}).siblings("div").hide();
});
$('.list li').mouseleave(function(){
$('.b').hide();
});
</script>
</body>
</html>