have i the right code for the vdo cdr 500?

hi all, this is my first ever vauxhall, after driving for around 20 yrs...it had a basic radio cassette in it, i bought a vdo cdr 500 off ebay....model number 24469302 s/n gm050021566634.....code 9065...i have tried it twice so far, i am now down to 8 attempts left...i enter the code, press the AS button til the beep, then it just goes down to the next attemp....is the code right?.....could really do with a bit of help please ..cheers