<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>jQuery 遮罩层</title>
<style type="text/css">
#overlay {
background: #000;
filter: alpha(opacity=50);
opacity: 0.5;
display: none;
position: absolute;
top: 0px;
left: 0px;
100%;
height: 100%;
z-index: 100;
display:none;
_ padding: 0px 0px 0px 5px; background-image: initial; background-position: initial; background-size: initial; background-repeat: initial; background-attachment: initial; background-origin: initial; background-clip: initial; border-left: 3px solid rgb(108, 226, 108); line-height: 20px; 640px; clear: both; border-radius: 0px !important; border-top: 0px !important; border-right: 0px !important; border-bottom: 0px !important; border-image: initial !important; bottom: auto !important; float: none !important; height: auto !important; left: auto !important; outline: 0px !important; overflow: visible !important; position: static !important; right: auto !important; top: auto !important; vertical-align: baseline !important; box-sizing: content-box !important; font-family: Consolas, "Bitstream Vera Sans Mono", "Courier New", Courier, monospace !important; min-height: auto !important; color: gray !important;">#a0a0a0; /* 解决IE6的不透明问题 */
}
</style>
<script type="text/javascript" src="jquery-1.7.2.min.js"></script>
<script type="text/javascript">
function showOverlay() {
$("#overlay").height(document.body.scrollHeight);
$("#overlay").width(document.body.scrollWidth);
$("#overlay").fadeTo(200, 0.5);
$(window).resize(function(){
$("#overlay").height(document.body.scrollHeight);
$("#overlay").width(document.body.scrollWidth);
});
}
function hideOverlay() {
$("#overlay").fadeOut(200);
}
</script>
</head>
<body>
<button onClick="showOverlay();" style=" 100px; height:60px; margin:40px auto 40px auto; display:block;">打开遮罩层</button>
<button onClick="hideOverlay();" style=" 100px; height:60px; z-index:101; display:block; position:absolute; left:10px; top:10px;">关闭遮罩层</button>
<div style="height:10000px;"></div>
<div id="overlay"></div>
</body>
</html>