When I drive my Mercury Mystique 1995 (v4) the brake lights dont come on,

[Redhwan]

whats the problem? The left and the right signals works and when I press the brakes ,only the brake lights for back window only lights up( back window). The two brakes lights in the middle dont light up. I replaced blubs but only to find out it was the reverse lights. I tried looking for a socket for a bulb cant seem to find one. Any suggestion to what the problem might be? Thanks