iframe高度自适应

< iframe src="index.html" id="iframepage" frameborder="0" scrolling="no"
marginheight="0" marginwidth="0" onLoad="iFrameHeight()"> iframe >

function iFrameHeight() {
var ifm= document.getElementById( "iframepage" );
var subWeb = document.frames ? document.frames[ "iframepage" ].document : ifm.contentDocument;
if (ifm != null && subWeb != null ) {
   ifm.height = subWeb.body.scrollHeight;
   ifm.width = subWeb.body.scrollWidth;
}

}