code needed for my Ka3 radio?

hiya - i really hope that you can help! iv just put back the original stereo in my ka as i'm looking to sell it, but i don't have the code for the radio :(
the serial number is : M006913 and the Model 6000 CD RDS
i would be most grateful if you could help me find the code! :)
Thanks
Lucy

Lucy
May 2008