Pokemon Shiny Gold Vba Codes In Pokemon Shiny Gold, How Do You Enter Gameshark Codes For VBA?

In Pokemon Shiny Gold, how do you enter gameshark codes for VBA? - pokemon shiny gold vba codes

I have some sites with code like the following:
http://www.supercheats.com/gameboy/pokem ...
But I do not know how to enter. If you do, or not logged on, or simply will not work. Do I need a teacher first code? HELP!