Ford Focus lock problems

I have an '02 Ford Focus, and recently my passenger side door locked and won’t unlock manually or through the door controls. I would appreciate any help concerning the cause of this problem and any possible remedies.

[b]The inside door panel is going to have to come off to look inside to find out what happened. But I’ll bet one of those cheap plastic retainers that holds the lock rod to the latch broke, and now the rod is no longer attached to the lock mechanism.

Tester[/b]

Crazy as it sounds, try taking the battery cables off the battery. It will reset your electronics. You will have to reset your radio, but it is worth a shot.
Worked for us a few times on our '87 Park Ave, until the door’s just plain rusted shut.