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

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

function iFrameHeight() {

    var ifm = document.getElementById("frame");

    var subWeb = document.frames ? document.frames["frame"].document : ifm.contentDocument;

    if (ifm != null && subWeb != null) {

        ifm.height = subWeb.body.scrollHeight;

        ifm.width = subWeb.body.scrollWidth;

    }

}

</script>

$("#frame").load(function(){

    var mainheight = $(this).contents().find("body").height()+30;

    $(this).height(mainheight);

});