<!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>
<title>无标题页</title>
</head>
<body>
<div style="width:2000px;height:2000px;"></div>
<div id="div" style="position:absolute; background-color:Green; width:100px; height:100px;"></div>
</body>
</html>
<script type="text/javascript">
function $(id){return document.getElementById(id);};
var div = $("div");
function reset()
{
var d = document.documentElement;
// 首先取得页面现在的左上角相对位置
var x1 = d.scrollLeft;
var y1 = d.scrollTop;
var w1 = d.clientWidth;
var h1 = d.clientHeight;
// 取得浮动层的信息
var w = parseInt(div.style.width);
var h = parseInt(div.style.height);
var x = Math.ceil((w1 - w)/2) + x1;
var y = Math.ceil((h1 - h)/2) + y1;
// 设置位置
div.style.left = x;
div.style.top = y;
}
window.onresize = reset;
window.onscroll = reset;
reset();
</script>
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
<title>无标题页</title>
</head>
<body>
<div style="width:2000px;height:2000px;"></div>
<div id="div" style="position:absolute; background-color:Green; width:100px; height:100px;"></div>
</body>
</html>
<script type="text/javascript">
function $(id){return document.getElementById(id);};
var div = $("div");
function reset()
{
var d = document.documentElement;
// 首先取得页面现在的左上角相对位置
var x1 = d.scrollLeft;
var y1 = d.scrollTop;
var w1 = d.clientWidth;
var h1 = d.clientHeight;
// 取得浮动层的信息
var w = parseInt(div.style.width);
var h = parseInt(div.style.height);
var x = Math.ceil((w1 - w)/2) + x1;
var y = Math.ceil((h1 - h)/2) + y1;
// 设置位置
div.style.left = x;
div.style.top = y;
}
window.onresize = reset;
window.onscroll = reset;
reset();
</script>
我只要第一次出现时在中间。谢谢,你这个例子在IE下非常好。可以firefox下就不行了