Help!! Need code for factory stereo

Have owned a 91 jetta for two years-never had the battery out until
two days ago! Now the factory radio requires a code to make it
work, and I don't have any owner's manual or any code for the car!
The stereo say's "design" on it and the car's V.I.N. is:
3vwrazigomm041840 Please help so I don't have to pay the dealer 40$
to give me the code!!