Rare Pokemon In Emerald I Can't Buy Rare Candies In Pokemon Fire Red And In Pokemon Emerald Using My Game Shark?

I can't buy Rare Candies in Pokemon Fire Red and in Pokemon Emerald using my Game shark? - rare pokemon in emerald

I have a shark game, but when I try to buy rare candies in fire red and the game ends emerald. How can I seldom sweets to the interruption of the game?