Is your car a SE equipped with factory power door locks? If so check the factory actuator to see if it is still functioning (never seen a OEM fail but you never know).
If your car has a aftermarket keyless entry/alarm setup using aftermarket door actuators you need to look for something attached to the steel rod that moves the locking mechanism back and forth. Should look like a box with a accordion thing on the opposite end. Make sure that the clamps on the door actuator has not come loose and if the actuator is still working. You should be able to test this with the door panels off the door and pressing your remote. Just make sure you hold the door pin when testing.
If my description of the door lock actuator is confusing here is a link of what it should look similar too.
http://www.amazon.com/High-Power-Doo.../dp/B0002KR9PW