Instructions
Plug your Nintendo DSi game into the top of the Action Replay. Plug the Action Replay into the game slot on the Nintendo DSi. Turn on the console. The Action Replay will automatically identify the game you have inserted.
Highlight the "Add New Code" option and select it with "X." Use the Action Replay's virtual keyboard and the DSi's control buttons to select the numbers and letters that represent the code you're entering.
Use the Action Replay's virtual keyboard to enter a name that represents the code you're adding. This can be any name you want.
Press "Start" on the Nintendo DSi to save the addition of the new code. The code will now become a permanent entry in the game list for the game you are playing on the Nintendo DSi.