<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
<title>无标题文档</title>
<style type="text/css">
<!--
body {
background-color: #990000;
color: #FFFFFF;
}
#w {
height: 200px;
width: 300px;
margin-right: auto;
margin-left: auto;
filter:alpha(opacity=50);
background-color: #003366;
}
#top{position:relative;}
-->
</style>
</head>
<body>
dan
<div id="w">
    <div id="top">透明度50%</div>
</div>
</body>
 
</html>


后台控制div标签里面的内容


前台：
<div id="div1" runat ="server" ></div>
后台：
div1.InnerText=" 数据库里面得到内容";