css layout dilemma

I just ended up fixing the problem myself.

drop the absolute positioning and check out "faux columns" on google

I already know what faux columns are, but i remember doing a layout like this before were I re arranged some of my html and used an overflow property for the undernav so it went down with the content. but i forgot how to do that.
I wanna be able to achieve this without faux columns since the width of the layout is fluid.

It would be nice of you to have left the question that you originally posted and also posted how you managed to fix the problem so that others looking through these forums as a help guide would also know how you fixed the problem, and therefore how they could as well... rather than just saying it's sorted