文本框位置

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="gb2312">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=GB2312" />
<title>控件位置</title>
<style type="text/css">

</style>
</head>
<body>
<table border=1 width="500" height="500" cellpadding=0 cellspacing=0>
<tr>
<td align="center">
<div id="s" style="background:silver;cursor:hand">
Click here to show.
</div>
<input type="text" name="textfield" onclick="show(this)" /></td></tr>
</table>
<script language="Javascript">
var sUserAgent = navigator.userAgent;
var isOpera = sUserAgent.indexOf("Opera") > -1;
var isIE = sUserAgent.indexOf("compatible") > -1 && sUserAgent.indexOf("MSIE") > -1 && !isOpera;

function getAbsoluteOffsetTop(obj) {
var y = obj.offsetTop;
while (obj = obj.offsetParent) y += obj.offsetTop;
if(isIE){return y+21;}
else{return y+21+"px";}
}

function getAbsoluteOffsetLeft(obj) {
var x = obj.offsetLeft;
while (obj = obj.offsetParent) x += obj.offsetLeft;
if(isIE){return x;}
else{return x+"px";}
}

function show(obj)
{
var x=getAbsoluteOffsetTop(obj);
var y=getAbsoluteOffsetLeft(obj);

var s=document.getElementById("s");
s.style.display = "block";
s.style.top=x;
s.style.left=y;
}
</script>
</body>
</html>