brake lights. centre works, main don't

I have a 95 Buick Regal. Just did front brakes and now when I press the brake pedal the centre (trunk) light goes on but the main brake lights just stay on parking lights. Anyone had the same problem? How did you fix it ?

It's probably your signal switch. I have the same problem (haven't fixed it just yet). If I pull the signal switch control towards me (as if to turn on the high beams, but not all the way), all brake lights will work. If I use the signal lights at all they don't. That's my particular symptom, however. Since your rear window light is working, this means the brake switch is working, so the next likely culprit is the signal switch, because that switch's circuitry doesn't just deal with the signals; brakes run through it as well.