Peugeot 806 remote key fob not working.

I just recently accuired a 2000 plate 806 - but the remote central
locking will not operate.

I have had a trawl about the internet and found out about the spare
key in ignition - to position a then press remote large and small
buttons but this does not do anything.

I have purchased a second 806 remote of ebay to try and program that
as well but to no avail
(yes new batteries have been put in both Plib's)

Does anybody out there have any suggestions to what may be my problem

Many thanks
Nige