Please help me with Tarzan for Gameboy Color!

[jessie's mom]

My daughter has the Tarzan game for Gameboy color. We found cheat codes, but have no idea how to enter them into the game. There seems to be a code where you press the arrow keys in a sequence to get to the cheat menu, but the sequence never works...I don't know where to enter it. Does anyone here know?

Thanks!