<html>
<body>
<input type="button" value="sd" onclick="doThis();"/><br/>
<div >nContainer[0]</div>
<div >nContainer[1]</div>
<div >nContainer[2]</div>
<div >nContainer[3]</div>
<div >nContainer[4]</div>
<div />
<SCRIPT LANGUAGE="JavaScript">
function doThis()
{
var a = document.getElementById("111");
a.style.left=(document.body.clientWidth/2-a.clientWidth/2)+"px";
a.style.top=(document.body.scrollTop+document.body.clientHeight/2-a.clientHeight/2)+"px";
}
</SCRIPT>
</body>
</html>