Newbie needs help!?!?

This is probably a really stupid question, but I can't figure this out...How do I play games multiplayer? I've tried to play both Rockstar Table Tennis and MLB Power Pros in multiplayer mode. Both games have screens that say press a button to join in, but it doesn't say what button. The 2nd controller works on all the Nintendo games, so I know it's not a controller malfunction.Is there some certain button(s) to press to join the 2nd controller into these games?Any help would be much appreciated! It's a little embarassing asking a question like this...but I thought I might as well go straight to the experts!Newbie needs help!?!?
From my experience you can press any button on the 2nd controller to activate it in-game.Newbie needs help!?!?
Man, so what am I doing wrong? I press every single button and button combination available...
Maybe it's different for those games, I don't know. Hopefully someone here who has played those games can help. But with games like Mario Strikers and even VC games, all I have to do is press a button on the second controller to get it to work.Try pressing the HOME button while in-game and tweak both controllers that way. You should be able to set which player is set to which controller. You have to press the 1 and 2 buttons or something along those lines. It should make more sense if you just go in and try it.
Anything?
I think you should de-config both controls, and then config them again, I had an almost similar problem