how can I set my right side bar to the the exact width of the ad?

[stuartforum]

hi ,how can I set my right side bar to the the exact width of the ad?
I know i have to make a custom grid and flatten it and everything but once I flattened it i just see the html codes and div tags and i have no idea on how to set the width of the right side bar... is there any tutorials out there which could help ?
thanks
www.stuartforum.com

[nitra1000]

How much do you know about css? It would involve editing the css templates to widen the blocks