<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> 
<HTML> 
<HEAD> 
<TITLE> New Document </TITLE> 
<META NAME="Generator" CONTENT="EditPlus"> 
<META NAME="Author" CONTENT=""> 
<META NAME="Keywords" CONTENT=""> 
<META NAME="Description" CONTENT=""> 
<style type="text/css"> 
.maskStyle { 
background-color:#B8B8B8; 
z-index:1; 
filter:alpha(opacity=50); 
opacity:0.8; 
position:absolute; 
text-align:center; 
color:blue; 
font:bold 1em "宋體",Arial,Times; 
height:25px; 
font-weight:bold; 
overflow:hidden; 

} 
</style> 
</HEAD> 
<script type="text/javascript"> 
function creatMaskLayer(effectItem,showText) { 
divItem = document.createElement("div"); 
divItem.className="maskStyle"; 
divItem.style.lineHeight=effectItem.offsetHeight+"px"; 
divItem.innerText=showText; 
divItem.style.width=effectItem.offsetWidth; 
divItem.style.height=effectItem.offsetHeight; 
divItem.style.top=effectItem.offsetTop; 
divItem.style.left=effectItem.offsetLeft; 
return divItem; 
} 
function setMask() { 
var effectItem = document.getElementById("test"); 
var existMaskItem = findMaskItem(effectItem); 
if(existMaskItem) { 
return; 
} 
var showText = "加載中..."; 
effectItem.appendChild(creatMaskLayer(effectItem,showText)); 
} 
function removeMask() { 
var effectItem = document.getElementById("test"); 
var maskItem = findMaskItem(effectItem); 
if(maskItem) { 
effectItem.removeChild(maskItem); 
} 
} 
function findMaskItem(item) { 
var children = item.children; 
for(var i=0;i<children.length;i++) { 
if("maskStyle"==(children[i].className)) { 
return children[i]; 
} 
} 
} 
</script> 
<BODY> 
<input type="button" value="蒙灰" onclick="setMask()"/> 
<input type="button" value="取消蒙灰" onclick="removeMask()"/> 
<br> 
<div id="test" style="border:1px solid;width:300px;height:300px"> 
蒙灰我吧 
<input type="button" value="測試是否還能點擊" onclick="alert('OK!')"/> 
</div> 
</BODY> 
</HTML>

解釋一下代碼中比較重要的地方。

.maskStyle是蒙灰層的樣式

其中
在CODE上查看代碼片派生到我的代碼片