JQuery UI resizable example

HTML

<div>

<div id="resize" class="demodiv">Resize me!</div>
<iframe id="IframeId" src="http://fiddle.jshell.net/gnel/xkHFP/show/" scrolling="no"></iframe>

</div>

CSS

.ui-resizable-helper {
    border: 1px dotted #999;
}
#resize {
    background-color: #ccc;
}
.demodiv {
    height: 150px;
    width: 150px;
    float: left;
    margin-left: 5px;
}

JavaScript

$('#resize').resizable({
    helper: "ui-resizable-helper",
    grid: [10, 10]
});
$("#IframeId").load(function() {
    $(this).height( $(this).contents().find("html").height() );
});