I have been battling on for hours with this problem.
What I would like to achieve:
My Website (yes I know it is crap) is working mostly fine all round however I would like to have the Glossary in the side bar to fill the remaining height under the "Featured Website" given the altering sizes of the main text in the middle of the page, and if the main text isn't that long (like on the index) to have a scroll bar in the Glossary in the side bar.
I.e. the iFrame which holds the glossary in the sidebar wants to be the same height as the "MainContent" cell minus a few pixles.