Audio Systems: infinity stereo system, negative battery cable, mitsubishi spyder

Question
We just bought our son a 97 Mitsubishi Spyder with the infinity stereo system.  While trying to figure out the code (which we now know) I somehow hit a button that caused the display to read oFF.  We have not figured out how to get back to the screen that ask for the code, any ideas?

Answer
Yes!
Get rid of that 9 year old mobile stereo system asap.

As to the code screen, call a dealer for specifics, but usually, removing the negative battery cable and reattaching it after a few moments will make the radio prompt you for a an unlock code.

Jm