I have an 97 e36 4dr and shortly after I bought my car I took my neighbors kids out to lunch. Well shortly after exiting the restaraunt my sons friend tried to open the rear passanger door and the door would not open. I assumed the child lock must be on but it wouldn't open from the outside either. I tried locking and unlocking the doors however to no avail the door still would not open. Anyone have any idea what might be wrong or how to fix it?