div出现在屏幕正中央的同时，锁定页面
<html> <head> <title></title> <meta http-equiv="content-Type" content="text/html;charset=gb2312"> <!-- 把下面代码加到<head>与</head>之间--> <style type="text/css"> .black_overlay { display: none; position: absolute; top: 0%; left: 0%; width: 100%; height: 100%; background-color: black; z-index: 1001; -moz-opacity: 0.8; opacity: .80; filter: alpha(opacity = 80); } .white_content { display: none; position: absolute; top: 25%; left: 25%; width: 50%; height: 50%; padding: 16px;/** border: 16px solid orange; **/ background-color: white; z-index: 1002; overflow: auto; } </style> </head> <body> <!--把下面代码加到<body> 与</body>之间--><input type="radio" onclick="document.getElementById('light').style.display='block'; document.getElementById('fade').style.display='block'"> <div id="light" value="关闭" onclick="document.getElementById('light').style.display='none';document.getElementById('fade').style.display='none'"></a> </div> <div id="fade" class="black_overlay"> </div> </body></html>?这个效果很好的大家可以去试试很多地方用的到！