<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Untitled Document</title>
<style type="text/css">
body{ margin:0; padding:0;}
.card{ width:200px; height:100px; background:#eee; border:1px solid #555; position:absolute; display:none;}
.test{ font-size:12px;}
.test li{ height:20px; width:100px; background:#eee; text-align:center; line-height:20px; margin-bottom:600px; list-style:none; cursor:pointer;}
</style>
<script type="text/javascript">
window.onload = function(){
var liArr = $("test").getElementsByTagName("li");
for(var i=0;i<liArr.length;i++){
liArr[i].onmouseover = function(){
$("card").style.display = "block";
var sh = document.documentElement.scrollTop || document.body.scrollTop;
var tx = this.offsetLeft;
var ty = this.offsetTop;
var th = this.offsetHeight;
var ch = $("card").offsetHeight;
$("card").style.left = tx + "px";
$("card").style.top = (ty - sh > ch ? ty-ch : ty + th) + "px";
}
liArr[i].onmouseout = function(){
$("card").style.display = "none";
}
}
}
function $(id){
return document.getElementById(id);
}
</script>
</head>
<body>
<div class="card" id="card"></div>
<div class="test" id="test">
<ul>
<li>测试</li>
<li>测试</li>
<li>测试</li>
</ul>
</div>
</body>
</html>
