提交窗体后滚动条位置保持不变

<script language="javascript">
<!--
function window.onload()
{
if(arr=document.cookie.match(/scrollTop=([^;]+)(;|$)/))
document.body.scrollTop=parseInt(arr[1]);
}
function window.onbeforeunload(){
document.cookie="scrollTop="+document.body.scrollTop;
}
//-->
</script>
</HEAD>