是Iframe高度自适应

<style>
.iframestyle
{
 height:expression(1);
 aho:expression(autoResize())
}
</style>
<script>
function autoResize()
{
  try
  {
  document.all["main"].style.height=main.document.body.scrollHeight
  }
  catch(e){}
  }
  </script>

<iframe name="main" src='aa.htm' marginwidth="0" marginheight="0" frameborder="0" scrolling="no" width="100%" class="iframestyle"></iframe>