This works for me (mostly).
Put this at the bottom of your page.
The first half is from ???, and works when there is html in the iframe.
The second half sets the iframe to page height (not content height), when iframes class is iframe_fullHeight. You can use this if the content is a PDF or other such like, but you have to set the class. Also can only be used when being full height is appropriate.
Note: for some reason, when it recalculates after window resize, it gets height wrong.
