radio code?

i have a 51 reg peugeot expert van on replacing the battery the peugeot radio cassett player now requires a code i have entered some random codes however i have noticed each time a small number in the right side of the screen increases it stands at 3 this is as many times i have enterd codes a friend say this only gives you so many chances then it will lock, he says as the number is 3 ie all the trys i had done it my just need the default code so if anyone has this please help me bring back the music in my cab, by the way on the front of the radio is 6 buttons no 1-6 if this helps many thanks.