弹出层（Div）屏蔽父窗口并且让父窗口变暗
<html>
<head>
<script>
function locking(){
document.all.ly.style.display="block";
document.all.ly.style.width=document.body.clientWidth;
document.all.ly.style.height=document.body.clientHeight;
document.all.Layer2.style.display='block';
}
function Lock_CheckForm(theForm){
document.all.ly.style.display='none';document.all.Layer2.style.display='none';
return false;
}
</script>
</head>
<body>
<img src="http://powereasy.net/skin/since07/images/sf_cms_banner1.jpg">
<p align="center">
<input type="button" value="系统锁定" onclick="locking()">
</p>
<div id="ly" style="position: absolute; top: 0px; filter: alpha(opacity=60); background-color: #777;
z-index: 2; left: 0px; display: none;">
</div>
<!-- 浮层框架开始 -->
<div id="Layer2" align="center" style="position: absolute; z-index: 3; left: expression((document.body.offsetWidth-540)/2); top: expression((document.body.offsetHeight-170)/2);
background-color: #fff; display: none;" >
<table width="540" border="0" cellpadding="0" cellspacing="0" style="border: 0 solid #e7e3e7;
border-collapse: collapse">
<tr>
<td style="background-color: #73A2d6; color: #fff; padding-left: 4px; padding-top: 2px;
font-weight: bold; font-size: 14px;" height="27" valign="middle">
[ 警 告 ]
</td>
</tr>
<tr>
<td height="130" align="center">
<input type="button" value=" 确定 " onclick="Lock_CheckForm(this);">
</td>
</tr>
</table>
</div>
<!-- 浮层框架结束 -->
</body>
</html>
<head>
<script>
function locking(){
document.all.ly.style.display="block";
document.all.ly.style.width=document.body.clientWidth;
document.all.ly.style.height=document.body.clientHeight;
document.all.Layer2.style.display='block';
}
function Lock_CheckForm(theForm){
document.all.ly.style.display='none';document.all.Layer2.style.display='none';
return false;
}
</script>
</head>
<body>
<img src="http://powereasy.net/skin/since07/images/sf_cms_banner1.jpg">
<p align="center">
<input type="button" value="系统锁定" onclick="locking()">
</p>
<div id="ly" style="position: absolute; top: 0px; filter: alpha(opacity=60); background-color: #777;
z-index: 2; left: 0px; display: none;">
</div>
<!-- 浮层框架开始 -->
<div id="Layer2" align="center" style="position: absolute; z-index: 3; left: expression((document.body.offsetWidth-540)/2); top: expression((document.body.offsetHeight-170)/2);
background-color: #fff; display: none;" >
<table width="540" border="0" cellpadding="0" cellspacing="0" style="border: 0 solid #e7e3e7;
border-collapse: collapse">
<tr>
<td style="background-color: #73A2d6; color: #fff; padding-left: 4px; padding-top: 2px;
font-weight: bold; font-size: 14px;" height="27" valign="middle">
[ 警 告 ]
</td>
</tr>
<tr>
<td height="130" align="center">
<input type="button" value=" 确定 " onclick="Lock_CheckForm(this);">
</td>
</tr>
</table>
</div>
<!-- 浮层框架结束 -->
</body>
</html>