Honda Accord Stereo - Serial #

Hi,

Where do I find the serial number for the Honda Accord's stereo system?

I'm in Chicago and the recent cold killed the battery. When I jump started the car the stereo displayed "CODE" on the little screen. I looked in the manual which says that the code should have been written down in the manual (I'm the 2nd owner). It wasn't.

So the manual says to get the stereo's serial number and call the original dealer. Where do I find the the serial number? Any help would be great.

Thanks, HMC