Radio presets on my toyota camry 1998 will not...

Question

When I turn the car off, if I had the radio on, it isn't on when I start the car next time and my station presets won't stay programmed. Is there a battery that is in the radio that keeps the presets alive? I would have thought it got power from the car battery. This seems to be a common problem. I have seen a lot of people with the same problem on line. I just have not seen a solution.