You may want to check to see if your brake lights are working.
If they aren't , chances are the brake lamp switch that feeds current
to the shift interlock solenoid is bad.
Without the voltage from the brake lamp switch, the solenoid cannot
acuate to the unlock position allowing you to shift out of park.
I have seen this problem before and it is relatively easy to fix!!
Good luck and keep me posted on this thread!
Fordman