Action Replay Codes?!?

[moshe-b3]

i have made a copy of my Dance Dance Revolution Club append
game.
i havew downloaded the pach adn installd it.
after i burnd the cd with fire burner when i put it on it says that "software termnated console may have been modified"
i found the action replay codes on mega game
but i dont know what is action replay and i dont have a clue how to use this codes
Please help!!!
i have a mod chip (i dont know what type)
its a ps1

thank you
moses