<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<script language="javascript">
function showdialog()
{
var divmask=document.createElement("div");
divmask.style.cssText="position:absolute;left:0px;top:0px;100%;height:100%;z-index:4;background-color:yellow;filter:Alpha(opacity=80)";
document.body.appendChild(divmask);
}
</script>
</head>
<body topmargin="0" leftmargin="0">
<center>
<button id="test" onclick="javascript:showdialog();">
<br/>
弹出层
<br/>
</div>
</center>
</body>
</html>