(Moved)Multiplayer Problem

Ok, so I've coded a fighting game with a single player that can move, fight, and use all other basic functions. However, the way I coded the original program makes it hard to put in another player in the same set of code. Is there a way to create a set of code running seperately from my original code or perhaps have a form running in the background detecting keystrokes in order for another player to be added and both play simultaneously?

hmm im not to sure about how you should do this. But it could be done on the same form. But there is a lot more to doing something like this than first meets the eye. Plus i believe this should be in the Games Programming thread.