CSS Problems

Hi,

i have build a WP theme from scratch to get a small cms. now the only thing i can’t get to work ist simply keeping the sidebar and content area on the same height. i am unsure how to describe it, but the sidebar should “follow” the content areas height. ahh…just look at it here

my question is probably really stupid but i am desperate by now. i even considered entering a lot of [br] to achieve what i need- but there has to be something more elegant that i am just to blind to see…

any help would be very much appreciated…

thanks, julia