relay problems A4 1999

[Stevehough]

Hi Audi A4 1999 avant 1.9 tdi has an electrical problem. the fuses are fine but i guess it is the relays. items not working are 1. central locking 2. rear boot will not open (guess no power to the solonoid) 3. electric windows wont work
can you advise which relay would be best to change?
Cheers
Steve