How do you wireless connection for ds lite?

Let me just give an example of how it works:

1. My friend and I both have... let's say Mario Kart DS.

2. We want to play together, so we start Multiplayer Mode.

3. One is host (host game), all others are guests (join game).

4. I try to connect, so I stay in a radius of some 3 meters or something.

5. If I'm connected, my friend taps "Cut off" and we can start racing after selecting track etc.

Most games have a special multiplayer mode in the title screen.

Some games, like Pokémon Diamond for example, haven't, and you need to unlock it, beat the game, get to a certain place or level, buy it with points etc. Also, some games haven't just got a MM in the title screen, e.g. Pokémon Diamond, but here you need to go to the 2nd floor of a PokéCenter, so go to a certain place where you can connect or start multiplayer mode.

I hope this is clear and that this helped you :D