I am trying to add a sidebar on the left hand side of my phpbb2 forum so that I can insert an advertisement. I have found this and I tried it out, but the problem that I am having is that it makes the entire page bigger and creates a side to side scroll in the browser window. Can someone tell me how to add the sidebar to the left hand side, while at the same time shrinking the main section of the forum so that it all fits on the page without any side to side scrolling?