<script>
function autoResize()
{
try
{
document.all["inner"].style.height=inner.document.body.scrollHeight
}
catch(e){}
}
</script>
<iframe name="inner" src="xxx.asp" marginwidth="0" marginheight="0" frameborder="0" scrolling="no" width="100%" style="height:expression(1); aho:expression(autoResize())"> 
</iframe>
<iframe name="temp" height="0"></iframe>