I am trying to connect my Nintendo DS to my Wi-fi and I'm having trouble. Help!?

I am playing Pokemon Black and I hope to get pokemon from the dream world. I can't connect to WI-FI, though. I have a linksys router and I know both the SSID and the password. When I try to connect when scanning for a connection, I get error 51300. When I put everything in manually, I get error 51300. It's unavoidable for me? Am I missing something? Also, I'm no the best with computers, so be mindful when instructing me.