ERYSIAN'S PROFILE

New here, so please bear with me. This seemed like a relatively simple idea, but it's becoming far more complicated. It's a school setting, and your hero is moving right-left against a wall while the 'coach' (an NPC) throws balls at him which he will try to dodge x number of times, winning prizes for dodging so many balls and so forth. Perhaps one of the problems is that the coach is also simultaneously moving right-left from his position and firing these balls at you. I set up the coding to start the ball at Coach's x and y, then shoot straight up every so often, followed by a check if it matches your x-y to see if that's a hit or dodge. One prob is that it refuses to acknowledge that the ball's Y has changed at all once it moves, so it can never match Hero's Y pos! Any ideas on how to resolve this?
Thanks