How do you get Wi-Fi for Yu-Gi-Oh world championship 2008?

If you go to world championship mode, you will see an icon of a DS and wireless signal, tap it and select wifi connection setup, then search for an access point(your home wireless network) and connect to it, you then go to wifi connection and you should connect, if you do not have a wireless network you can do to McDonald's and connect there(no setup required), or you can connect to another place but it will most likely require setup. Not all hotspots are compatible.