实现iFrame自适应高度，原来很简单！

<iframe id="aspx" name="aspx" width="100%" 

onload="this.height=aspx.document.body.scrollHeight" 

frameborder="0" src="index.htm"></iframe>

看到了吧，关键就在于！
下边这个正确~~~~~~~~~~~~~

<script language="javascript" type="text/javascript">

function dyniframesize(down) { 

var pTar = null; 

if (document.getElementById){ 

pTar = document.getElementById(down); 

} 

else{ 

eval('pTar = ' + down + ';'); 

} 

if (pTar && !window.opera){ 

//begin resizing iframe 

pTar.style.display="block" 

if (pTar.contentDocument && pTar.contentDocument.body.offsetHeight){ 

//ns6 syntax 

pTar.height = pTar.contentDocument.body.offsetHeight +20; 

pTar.width = pTar.contentDocument.body.scrollWidth+20; 

} 

else if (pTar.Document && pTar.Document.body.scrollHeight){ 

//ie5+ syntax 

pTar.height = pTar.Document.body.scrollHeight; 

pTar.width = pTar.Document.body.scrollWidth; 

} 

} 

} 

</script>

<iframe src ="/default2.aspx"  frameborder="0" 

marginheight="0" marginwidth="0"  frameborder="0" 

scrolling="auto" id="ifm" name="ifm"  

onload="javascript:dyniframesize('ifm');"  width="100%">

</iframe>