How do I make the width of forum smaller
 

Okay, I am running vbadvanced for my site, adcolumns for my advertising. I have put in a conditional so that adcolums only shows up on my forum pages, not on site pages. I also have a banner on the top of my page that is 980 pixels wide, The forum width is also set at 980 pixels wide. If I add the adcolumns then the adcolumns goes off of the viewable page and creates a need for side scrolling, I do not want to make people do this and I want it to be viewable. My adcolum is 150 pixels wide. If I change the forum width to 830 then my navbar is messed up and it centers it, so part of the adcolumns doesn't show up correctly. I have been trying to get this to work properly now for 4 days. Tried changing tons of stuff, Can anyone help a guy out with what I need to do?

at 980 pixels you're asking for horizontal scrolling from probably 30 to 40% of your visitors anyway. You should remain under 770 pixels always. or use expandable tables.