<script type="text/javascript">
 function SetCwinHeight(){
  var bobo=document.getElementById("bobo"); //iframe id
  if (document.getElementById){
   if (bobo && !window.opera){
    if (bobo.contentDocument && bobo.contentDocument.body.offsetHeight){
     bobo.height = bobo.contentDocument.body.offsetHeight;
    }else if(bobo.Document && bobo.Document.body.scrollHeight){
     bobo.height = bobo.Document.body.scrollHeight;
    }
   }
  }
 }
</script>
<iframe width="100%" id="bobo" onload="Javascript:SetCwinHeight()" height="1" frameborder="0" src="/default.asp?cateID=1"></iframe>