Problem with wifi on mac

[BigtimeRyan]

My laptop is a relatively new around 6 months old Macbook pro on Lion. I was away on holiday and one day I kept trying to connect to my cousins wifi and it kept saying it could not find an ip address and there was an exclamation mark on the wifi icon at the top. (The internet wassn't working). Finally after fiddling around I connected but the web pages wouldn't load and my brothers think its something to do with my 'Wifi card'. I got home expecting it to work on my router back in London and it did not work. Web pages still not loading. Any help or suggestions?
Thank you
Taking it to be repaired tomorrow :)

[BigtimeRyan]

Taken to shop this morning. Fixed :D

[Red]

Glad you got it fixed. Apple's support is sooo good.

[BigtimeRyan]

Exactly, unlike sulake's