Radio Code for 1991 VW JETTA DIESEL...NEEDED..HELP!!

[navajobeng]

We just bought a 'used' 91' Jetta Diesel, it was advertised as 'radio not working'...No biggie. UNTIL my husband was able to power it up and received the text message "CODE"
A little searching on the net, finds us seeking the 'unlock code' to get the radio to function fully/properly. Also..once we have the code, are unsure of the steps to take to enter it.
Not sure of the BRAND NAME..it only says VW DESIGN on the front (Cassette door)...
MODEL# 000 035 188BP
SERIAL# 33734

Any help would be MOST APPRECIATED!!!
Thanks