iframe的height自动调整,不出现滚动条

 2。让iframe的height自动调整以适应里面的内容，不出现滚动条。
在父页面中
<div id="div1"><iframe name=...  src=... style="Z-INDEX: 2; VISIBILITY: inherit; WIDTH: 100%; HEIGHT: 100%" frameborder="0" scrolling="no"></iframe></div>
    
iframe中页面:
function window.onload()
{
  var div = window.parent.document.getElementById('div1');
  div.style.height=document.body.scrollHeight+20;
}

3.使div在dropdownlist之上︰

<div>
<iframe src="javascript:false" style="Z-INDEX:-1; FILTER:progid:DXImageTransform.Microsoft.Alpha(style=0,opacity=0); LEFT:0px; VISIBILITY:inherit; WIDTH:158px; POSITION:absolute; TOP:0px; HEIGHT:110px">
</iframe>
</div>