Need help on cheats for Halo on PC!!!

Ok, so I have a hard time with cheating in the Halo PC. I talked to people and they said to do this.....

Open the properties window of the Halo shortcut and add ' -console –devmode' after the target. Start the game with the -console -devmode command line parameter. During game-play press '~' to display the console window, then enter one of the following codes to activate the corresponding cheat function.

Is this how it is supposed to be done, because it does not work for me.