JavaScript:iframe自动适应高度

<iframe src="news.htm" id="newsiframe" marginwidth="0" marginheight="0" frameborder="0" scrolling="no" width="100%" onload="this.height=0;var fdh=(this.Document?this.Document.body.scrollHeight:this.contentDocument.body.offsetHeight);this.height=(fdh>10?fdh:10)"></iframe>
注：onload字段中的数值“10”为Iframe最低高度值，可自定义！