if you run 'ifconfig wlan0 up' does it give you an error?

I know this sort of bridging between the actual NIC and Backtrack but I was wondering if someone could help me out with this.

I have managed to get the built-in wireless on my laptop working...

I just installed Backtrack 5R1 on my laptop today and everything worked well out of the box and even the wireless was on, but then I shut it down and brought it home and now I'm not getting any...