Answer by Macho Matt for Resizing an iframe based on content

The solution on http://www.phinesolutions.com/use-jquery-to-adjust-the-iframe-height.html works great (uses jQuery):

<script type=”text/javascript”>  $(document).ready(function() {    var theFrame = $(”#iFrameToAdjust”, parent.document.body);    theFrame.height($(document.body).height() + 30);  });</script>

I don't know that you need to add 30 to the length... 1 worked for me.

FYI: If you already have a "height" attribute on your iFrame, this just adds style="height: xxx". This might not be what you want.