<!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">
<!--
.mydiv {
width: 1280px;//图片background.gif的宽度
height: 720px;//图片background.gif的高度
left: 50%; /*FF IE7*/
top: 50%; /*FF IE7*/
margin-left: -640px !important; /*FF IE7 该值为本身宽(width)的一半 */
margin-top: -360px !important; /*FF IE7 该值为本身高(height)的一半*/
margin-left: 0px;
margin-top: 0px;
position: fixed !important; /*FF IE7*/
position: absolute; /*IE6*/
_top: expression(eval(document . compatMode &&
document . compatMode == 'CSS1Compat') ?
documentElement . scrollTop + ( document .
documentElement . clientHeight-this . offsetHeight )/ 2 : /*IE6*/
document . body . scrollTop + ( document . body .
clientHeight - this . clientHeight )/ 2 ); /*IE5 IE5.5*/
_left: expression(eval(document . compatMode &&
document . compatMode == 'CSS1Compat') ?
documentElement . scrollLeft + ( document .
documentElement . clientWidth-this . offsetWidth )/ 2 : /*IE6*/
document . body . scrollLeft + ( document . body .
clientWidth - this . clientWidth )/ 2 ); /*IE5 IE5.5*/
}
-->
</style>
</head>
<body>
<img src="background.gif" class="mydiv" />
</body>
</html>