MarioKart DS How do I race with a friend?

[NintendoFreak]

Well Im a bit dumb lol I know everything about nintendo (not to sound big) but I just cant get how to play someone when U have there friend code I know that ICON apears but then what ? Plus rep for any answers

[HUGECOOL]

Afyet you've connected to the WiFi service, choose 'Friends' from the screen. If your friend is online and has also chosen the 'Friends' race mode, you and them will be able to race against each other.