How do you delete files on petz catz clan

I figured it out. When you turn on the DS and select the DS game to play, the first thing that appears from the game is "Licensed by Nintendo" with a white background. When that is on the screen (its there for about 3 seconds) that's when you push the button combo L, X, B, SELECT all together at the same time. Then it will ask you if you want to start a new game or not.
i tried that, because i had the same problem, and it worked but the adoption center wasnt there. like i needed to unlock it. so i tried deleting the game again and it still said that i needed to unlock the adoption center D;