<!DOCTYPE html>
<html>
<head>
<title>遮罩函数</title>
<meta charset="UTF-8"/>
<style type="text/css">
#zhezhao{
width: 100%;
height: 100%;
background: gray;
display:none;
position: absolute;
left: 0;
top: 0;
}
#contains{
width: 520px;
height: auto;
background: #fff;
display: none;
position: absolute;
left: 400px;
top: 70px;
}
</style>
<script type="text/javascript">
function show(){
document.getElementById("zhezhao").style.display="block";
document.getElementById("contains").style.display="";
document.getElementById("zhezhao").style.filter="Alpha(Opacity=50)";
}
function hide(){
document.getElementById("zhezhao").style.display="none";
document.getElementById("contains").style.display="none";
}
</script>
</head>
<body>
<input type="button" value="显示遮罩" onclick="show()"/>
<div id="zhezhao">
<form>
<p><label>请输入用户名:</label><input type="text" name="name"/></p>
<p><label>请输入密码:<input type="password"name="pwd"/></label></p>
<input type="button" value="隐藏遮罩" onclick="hide()"/>
</form>
</div>
<div id="contains">
</div>
</body>
</html>MySQL创建计算字段——MySQL系列（五）,布布扣,bubuko.com
原文：http://blog.csdn.net/vvhesj/article/details/22749957