Control contents in sliding effect

Control contents in sliding effect

Hello there,

First off i'm really happy with jQuery! Very nice stuff, glad i found it. 
Then my question. I'm making a site where i have multiple menu bars sliding up or down showing content. I'm wondering if there is a way to control the contents of the sliding div because now it slides up slightly aswell as the div gets closed (or opened), but i'd like it to stay where it is.
So basicly i want the contents of the sliding div not to move when its animated, is that possible? Maybe with another jquery command?
Here's a testpage of the site I'm working on:  http://sander.walvismosmans.nl/meesterbouw/

Hope someone got an idea :)

Thanks in advance, greetz,

Sander