How do i unfreeze the buttons on my pioneer mosfet 50wx4 car audio system?

[John]

You probably locked the buttons.
If you still have your manual, look up how to lock and unlock the buttons.

 

[Kristin D]

I tried changing the time and then all of a sudden none of the buttons would work. It plays CDs if i put them in but i cant change the tracks or change it to the radio because all of the buttons seem to be frozen. Is there anyway i can reset it? please help!