I have installed Ubuntu 14.04 on my laptop. When I plug in the ethernet cable the internet works fine, but I can't see any wireless network in the networking manager. The wifi switch is definitely on on my laptop! It's a Dell XPS M1330. I'm not sure what the network card is - how can I find out?

nm-tool gives me this:

NetworkManager Tool

State: connected (global)

- Device: eth0  [Wired connection 1] -------------------------------------------
  Type:              Wired
  Driver:            tg3
  State:             connected
  Default:           yes
  HW Address:        00:23:AE:28:FE:A2

  Capabilities:
    Carrier Detect:  yes
    Speed:           100 Mb/s

  Wired Properties
    Carrier:         on

  IPv4 Settings:
    Address:         192.168.1.26
    Prefix:          24 (255.255.255.0)
    Gateway:         192.168.1.254

    DNS:             192.168.1.254