My car stereo is asking for a code after thecar battery went dead. Where do I find it?

So,
It won't even play- even through the auxiliary cable with the I pod. It's a Honda CRV. Does anyone know where I can find the code? Thanks in advance. Your advice is much appreciated.

Added (1). For those with the same problem, I was able to speak with the service manager at the dealership, and he was able to have me press the numbers 1 and 6 at the same time, and hold them down while pressing the power button simultaneously. A series of numbers came up. I then read him the numbers to him and he was immediately able to read me the code to enable the stereo again.
Voila!

So? Who starts off a question like that? Two options; 1. The code should be with the owner's manual portfolio, 2. Go down to the DEALER with PROOF of OWNERSHIP, and have them RETREIVE the CODE.

I have scoured the manual for the code, but will likely take it to the dealership if I can't figure it out. Also, I started off a question like that. Be kind to others. It will make your life happier. I sincerely appreciate your input, and hope that you have a wonderful day.

Just call your local Honda dealership with your vehicle info they'll give you the 4 digit code