Won't shift into gear

[toad]

Hey everyone I am new to the site and have a question on my sons 1996 Grand Prix SE 3100. It will not go into gear when you shift it from park. Reverse lights come on, I can start it in neutral, no key issues. It just won't go. Every once in a while I can get it to go into drive if I play with it long enough. Reverse is impossible...

Any thoughts? Thanks