2. Connect your Nintendo DS to your computer using the USB cable that came with the console.
3. Open the Action Replay MAX software on your computer.
4. Click the "Add New" button and select "Game Code" from the list of options.
5. Enter the GameShark code for the cheat you want to use in the "Code" field.
6. Click the "Add" button to add the code to the list of codes for your Nintendo DS.
7. Click the "Send to DS" button to send the codes to your Nintendo DS.
8. Start Pokémon Diamond on your Nintendo DS and load the game save file that you want to use the cheats on.
9. Press the Start button on your DS controller and then press the L + R buttons at the same time. This will open the cheat menu.
10. Use the D-pad to select the cheat you want to use and press the A button to activate it.
11. You can now use the cheat in your Pokémon Diamond game.