Did I make the Dark Aura ability correctly?

Can someone confirm if I made "Dark Aura" Correct?
(I don't really know much on scripting, so sorry if I made a dumb mistake)
CODE:
if isConst?(attacker.ability,PBAbilities,:DARKAURA) &&
(isConst?(type,PBTypes,:DARK)<----Is this to check if using a Dark move?
basedmg=(basedmg*1.3).floor
end

(And also one more thing, can I put this script anywhere? Or does it need to be in a specific spot? in PokeBattle_Move?)
Thank's

I think your trying to change the ability because it dose this. Powers up each Pokémon's Dark-type moves.