Car stuck in 3rd gear?

My friend has a 92-94(Not sure at the time) Plymouth Laser, I believe what happened was he was driving along, and when he stopped at his friends house, it didn't shift out of 3rd gear. Reverse works fine. We have NO idea what the problem is, and he doesn't want to take it to the shop because neither of us have the money. Any suggestions would be GREATLY appreciated. The car is an automatic, by the way.