Whats wrong with this script? for my Gun game

function if plyer KOS +1 give plyer next grade end
	grade = tool value ("1,2,3,4,5,6,7,8,9,10") -- These are the guns you can get so far
end

Sorry but this script does not make any sense whatsoever. functions need to be created like so

function SupDude()


end
--and can be called by saying the following
SupDude()

Please see here for more information on that.

Also, you did not define what plyer or KOS is to the script. Look for a free model leaderboard and see what you can learn from it.