1999 Escort--cannot push in release button on gear shift

I am unable to put my car into REVERSE, the button on the gear shift is stuck. Any suggestions?

If the lock button on your gear shift isn't working then you shouldn't be able to get the car out of park.
If it is in fact the locking mechanism in the handle, then it will simply have to be taken apart and repaired/replaced.
If you have the means to do it... just to check the function of the transmission... from under the car you can disconnect the shift lever from the transmission and change the gears by hand from underneath. If reverse is still stuck, then you have a different problem.

On my 97 Escort automatic there is a little round plastic plug on the shifter console. It is in the upper right hand corner. Pull that plug out and insert a long narrow screwdriver and push against the manual release lever. It will unlock the shifter so you can get it into reverse. Unless you step on the brake it will not shift out of park. Ford designed it this way so you wouldn't move while shifting into reverse. If the brake light switch is bad and your brake lights are not coming on this is why it won't shift out of park. I would check the fuse.