利用js让iframe框架自适应网页高度

<script language="javascript">
<!--
function setFrameHeight(obj){
 var win=obj;
 if (document.getElementById)
 {
  if (win  &&  !window.opera)
  {
   if (win.contentDocument  &&  win.contentDocument.body.offsetHeight)

    win.height = win.contentDocument.body.offsetHeight+"px";
   else if(win.Document  &&  win.Document.body.scrollHeight)
    win.height = win.Document.body.scrollHeight+"px";
  }
 }
}
-->
</script>

<iframe id="main" style="width:100%;" name="main" src="/" scrolling="no" frameborder="0" marginheight="0" marginwidth="0" onload="Javascript:setFrameHeight(this)"></iframe>
<br><br style="overflow: hidden; line-height: 10px">