1997 Pontiac Ignition Key wont come out

1997 pontiac grand prix,3.8, high miles. The ignition key would not come out. A friend told me that there was a button that I can push to get it to turn and get the key out. I had to take the plastic portion of the steering column to expose the button. I pushed it and the key locked and came out. What is the main problem? How can I fix this?
firefighter; Generally, it's a worn tumbler that causes this. If you have the VATS system, which I'm sure you do, the dealer will need to 'key' a new tumbler for you as your ignition key must match the new tumbler. However...(there's always a however)...if your steering wheel was turned when you shut the ignition off, it could have been in a 'bind'. Start the vehicle, turn the wheel back and forth a couple of times, allow it to 'relax' before turning off the igniton and into the lock position.
Loren
SW Washington To add: Old school on the ign switces. There's a small fingernail of metal that retracts when they tumblers are in totalol off position. Older veicles you could see the wear on the key from that.

Now and as Loren said if wheel was left turned hard with the power steeing you might not notice so much it can cause forces that as he suggested could release the key. Make sure buy feel that it's in the exact off position too.

Guess it's time to start suggesting folks try some lock lube as this is happening more often!! If the key hay chip unique to the car you may need help is the whole thing has to go for new,