alarm programming

Hi! If anyone can help, I would greatly appreciate it. I have a 2000 Grand Am with factory installed alarm system. The keyless entry works and so does the panic alarm, but the alarm doesn't sound if you try to open the door with out the remote or if you try to start the car with the alarm set. In other words, I don't think the alarm is setting at all. The horn doesn't even beep anymore when I go to lock the doors, (indicating the alarm is set). The dealership wants to charge my 150 just to LOOK at it! Please help. I don't know anything about cars so I apologize if i used incorrect terms...

Thanks