如何用js改变frame的scrolling属性


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>test</title>
<script>
if(window.top!=window) {
window.top.location.href= window.location.href;
}
</script>
</head>
<frameset rows="45,*" frameborder="no" border="0" framespacing="0">
  <frame src="top.html" name="topFrame" scrolling="No" noresize="noresize" id="topFrame" title="topFrame" />
  <frameset rows="*" cols="160,*" frameborder="no" border="0" framespacing="0">
<frameset rows="*,59" cols="*" framespacing="0" frameborder="no" border="0">    
<frame src="menu.html" name="leftFrame" scrolling="No" noresize="noresize" id="leftFrame" title="leftFrame" />
<frame src="bottom.html" name="bottomFrame" scrolling="No" noresize="noresize" id="bottomFrame" title="bottomFrame" />
    </frameset>    
      <frame src="default.html" name="mainFrame" id="mainFrame" title="mainFrame" /> 
  </frameset>  
</frameset>
<noframes>
<body>
</body>
</noframes>
</html>如上述HTML,在应用中,在default.html里面建立一个function,想隐藏mainFrame的scroll,但是试过很多种方法未成功,请高手指点
以下为失败方法
window.top.mainFrame.scrolling = 'no';
window.top.mainFrame.setAttribute("scrolling", "no");
window.top.mainFrame.frameElement.style.overflow='hidden';
window.top.mainFrame.frameElement.scrolling = 'no';