始终不变的问题

其中一个frame页面
<html>
<head>
<title>Untitled Document</title>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
</head><body bgcolor="#FFFFFF" text="#000000">
<SCRIPT language=JavaScript>   
function UpdatePosition(){   
if (document.all)   
Layer1.style.top = document.body.scrollTop; 
}   
setInterval("UpdatePosition()", 100);
</SCRIPT>
<div id="Layer1" style="position:absolute; width:300px; height:189px; z-index:1"> 
  <table width="190" border="1" cellspacing="0" cellpadding="0" height="114">
    <tr>
      <td>hgj</td>
    </tr>
    <tr>
      <td>ggggggg</td>
    </tr>
    <tr>
      <td>hgj</td>
    </tr>
  </table>
</div>
<p>f</p>
<p>f</p>
<p>f</p>
<p>f</p>
<p>f</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>f</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>f</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>&nbsp;</p>
<p>f</p>
</body>
</html>