I use Resolve carpet cleaner (in the spray bottle) on my carpet. But you can also try Oxy Clean. Comes in powder form in a small bucket. Test it on a small area first. You can get either of these cleaners at a regular grocery store, I believe.
Others may have more options for you too.

ETA: LOL, Caseysmom, you posted while I was still composing mine. Yes, Oxi Clean (I just looked and noticed I spelled it wrong before).