he doesn't need to go to the cheat forum
http://gbatemp.net/t116242-a-basic-guide-o...create-ar-codes

the concept is the same for all platforms
the most important you should have is LOGIC and PATIENT

no offense but most of them who attempted doesn't have both...

 

did you trigger the activator

 

yes.. like select, L, R, Up...

check what is the activator for the code
and then trigger it while you are in the game

 

well, as far as i know the cheat codes work with the patches
even after you patch them it should work
at least this is the case for "U"

when you say EU... which version is that?
F, I, S, G or E

EDIT: anyway, the codes in the databases are for clean rom aka non patched version of the game. In any case if the codes really don't work on your patch rom then you maybe you can try pokesav