WWE SmackDown vs. RAW 2008 Codes -

Cheat mode
Select "Cheat" at the "Options" menu and enter one of the following case-sensitive codes on the virtual keyboard to activate the corresponding cheat function. Note: Some European and Australian versions of the game do not have the "Cheat" option.

HHH's and HBK's DX costumes
Enter DXCostume69K2 as a code.

Kelly Kelly's bonus costume
Enter KellyKG12R as a code.