krysia

while i was changing the alternator belt my neighbour who was helping diconnected the battery,we forget that would mean the radio code would need to be re-entered,unfortnately i have lost the code,any ideas how to get the radio back. the car is a citroen xantia on a lreg plate,i bought it last year and have since lost or mislaid the book with the radio codes. hope someone can help. thanks in advance. krysia