100% of website in iFrame?

I’m running a page in an iFrame, and I want it to be able to scroll down for the whole length of the page that is loading into the iFrame. http://www.madatoms.com/themes/site/blog.html

Notice how it cuts off after a certain distance. I set a height to the height the page used to be, but I can’t be updating that every time a new post is added, that’s silly. Is there some sort of code that I can run that will check the height of the page it is loading, then figure out the height of the iframe from that?