If the car doesn't have too many miles on it (it's a 2002) you may be able to take it to the dealership to have them fix it under warranty. If it's out of warranty, you can problably remove the arm rest, door skin and then see if you can find the broken piece. It can probably be put back in place without a repair bill. Other possible reasons for the problem: If the car was hit on that side, the latch may have been broken. And, if this car had 4 doors, it might have a child safety latch that prevents it from being opened from the inside. I've never seen a 2 door with the feature, but check for a switch on the door panel.