Iframe自适应高度绝对好使的代码 兼容IE,遨游，火狐

<script type="text/javascript"> 
function reinitIframe(){ 
var iframe = document.getElementById("mainFrame"); 
try{ 
var bHeight = iframe.contentWindow.document.body.scrollHeight; 
var dHeight = iframe.contentWindow.document.documentElement.scrollHeight; 
var height = Math.max(bHeight, dHeight); 
iframe.height = height; 
}catch (ex){} 
} 
window.setInterval("reinitIframe()", 200); 
</script>