利用样式表的功能就能轻易实现
<SCRIPT>
function autoResize()
{
try
{
document.all["test"].style.height=test.document.body.scrollHeight
}
catch(e){}
}
</SCRIPT>
<IFRAME ID="test" SRC="ActorPictureList.aspx?ActorID=9371" FRAMEBORDER="0" STYLE="height:200; aho:expression(autoResize())"></IFRAME>