Another newbie question - How to get something outside main background to show?

[D.M.M.]

Hi, How do you get something to show in the browser that is outside the main background? I have the Xara 10 premium and set it to supersite, have tried clicking "scale to screen" and unclicking "scale to screen" (by the way, since neither worked, which should I have?).

I just want a small graphic that is in the background to extend slightly over the "edge" so to speak, of the main background box, nothing major (so I think).

Something like this website in the gallery:
Thank you!