96 Corvette Brake Question

I have a brake light problem with my 96 Corvette and this is my first time trying the message board for help. The 4 brake lights do not illuminate when pressing the brake pedal, however the center safety light in the middle does, the running lights and turn signals work fine. Is there a separate switch that controls the 4 round tails lights separate from the center light or could this be a grounding problem? I thought I would try the message board to see if anyone else has run into this problem before taking it to the garage.