What do you do when your action replay DSi says missing codes?

That is the same with me but,if you see a zero in the area where it says your codes should be,reset it by turning off you consol and holding in a and b.then turn it on and when you see action replay logo hold in start and select.if it doesnt have anything in the area where it says how many codes are on,welcome to my world.

actually,

You go to the code list and enter the game name and then when it says enter game code, enter the numbers. PS it might be automatically put in and you just press save.