Hi digadesign. I'm afraid "auto-fill" is a meaningless term. Could you specify what you mean?
I'm guessing you want the background to stretch down the right side. If so, you could consider using the faux columns method, with a repeating background image. For the bottom right curvy part, instead of making the footer image transparent, make the transparent bits white to cover over the orange going down the right side.
[PS: I've moved this thread to the CSS forum. ]