Multiplayer GBA games how to do it?

[Xena]

DS and his cousins have a couple of GBA games that are multiplayer and they have the link cable but they still can't do it, do you have to have a copy of the game each?

yes

Now that is pants Ive always wondered about that. While we are here, dds hamtaro game has virtual stickers on it, can a GB be plugged into the pc for printing?

yes

Really how???>

That is such a con. DS wants a pokemon game for christmas with comes with a wireless adapter and he can only use it with someone who has the same game?

yes

but there is a single player game on it as well