[I highly suggest you test your codes on something like a real game cart, if you still have anything that old, or on an emulator like VBA - also, GameYob currently only supports 14 strings of code, not full complex actual codes] This is very easy, and it is broken down into 3 steps: 1: The original code 2: If it is enabled or disabled 3: The name of the code First off, find the code for waht ever game you want, I'll go with Pokemon Crystal, because I'm hardcore. Lets try the shiny pokemon code: 910730D2 . From here, you format you code like this 1: Basic code 910730D2 2: Basic code + Enabled/Disabled 910730D2 0 - Disabled 910730D2 1 - Enabled 3: Basic Code + Enabled/Disabled + Name 910730D2 0Fight Shiny Pokemon - Yes, there is no space after the 0 or the 1. Saying you just want this code for now, save it as the name of your rom, mine is "06 Pokemon Crystal.gbc - in this case change the .gbc to .cht ["06 Pokemon Crystal.cht"]." Saying you want a longer code, this can be done, the only current restriction is that you can only have 14 lines of code per cheat file. Lets add a longer code like Walk Through Walls. 010AA3CE 0Walk Through Walls 1 010AA4CE 0Walk Through Walls 2 010AA5CE 0Walk Through Walls 3 010AA6CE 0Walk Through Walls 4 9100FAC2 0Walk Through Walls 5 9100FBC2 0Walk Through Walls 6 9100FCC2 0Walk Through Walls 7 9100FDC2 0Walk Through Walls 8 Just enable all codes at once when using a code like this, I suggest you always set codes to be disabled  to start out with, and just manage them while you are in game. Now lets get these rascals guys.