Radio says "CODE" 1998 Discovery LE

I disconnected my battery today, and when I reconnected it, started the car, the Radio displays "CODE" and won't play. Is there some code i'm soppused to put in? 

So you are saying you don't have your radio security code.
Go to your lock dealers service department and see if they can still get your number from Rover, if they can, you are i luck, if they can't it will be near impossible to recode your radio.