How To Write Cheats For Visual Boy How Do I Use Cheats For Pokemon Fire Red Using Visualboy Advance?

How do I use cheats for Pokemon Fire Red using Visualboy Advance? - how to write cheats for visual boy

I use Visual Boy Advance on Mac OSX, and every time I run into a gameshark code breaker or pots, then a ROM, only valid XXXXXXYYYYY said there is a way of tricks and traps I write badly? or whatever. Helpppp plzzzz