Power Locks

I have a 1994 Grand Am and am having some trouble with the power locks in the doors. The unlock switch works on both doors but the lock switch doesnt work on either door. If anyone has a suggestion of how to fix the problem please let me know.

Is this true about all the lock switches or just one? If it was all of them I'd be looking at fuses. If it were one, you can open up the door panel and take a look at the switch. Make sure it's getting power, etc..