<!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>
<title></title>
<style type="text/css">
#poplayer
{
position:absolute;
top:100px;
left:400px;
width:300px;
height:200px;
z-index:8888;
background-color:#9CAAC1;
}
#covered
{
position:fixed;
_position:absolute
z-index:888;
top:0px;
left:0px;
width:100%;
height:100%;
background-color:Black;
opacity:0.3;
}
</style>
</head>
<body>
<input type="text" value="底层" />
<div id="covered">
</div>
<div id="poplayer">
<input type="text" value="弹出层" />
</div>
</body>
</html>