Centering Background Image (HTML)

I need the code (HTML) to be able to center a background image in a table or cell and it not tile if the browser gets wider (or at least look that way). Just like this example ([login to view URL]). It must be simple. I use Frontpage. I am not a programmer but I know how to adjust the code. I need it now (asap). Should be extremely simple for an expert IMO. $30