Things You'll Need
Instructions
Enter the following code into your Action Replay DSi:
94000130 FCFF0000
62101D40 00000000
B2101D40 00000000
0000B5D4 0000000A
0000B5D8 00000000
D2000000 00000000
Start the game and press both the "L" and "R" buttons at the same time. Every time you press these buttons while the code is active, an Azure Flute will be deposited into your inventory.
Climb to the top of Mt. Cornet. You will be prompted to use the Azure Flute. Doing so will cause a staircase to appear, allowing you to ascend to the Hall of Origin, where you can battle and attempt to capture Arceus.