MacBook AirPort Connectivity Problem

I just got my MacBook and I my friend set it all up for me before I got it (I recieved it as a present). When I first turned it on it asked me if I wanted to connect to my Home Internet connection and I said yes, and it was connected for only a few seconds. I tried connecting again but no luck. I know the WEP password and my default connection comes up, but it says 'An Error Occured While Trying to Connect To 'Linksys'. Help?

if he set it up before hand it may have been configured to his home wireless network perhaps? if it's not that then check your router configuration.

Instead of WEP try using WPA