Something

interfaces :

# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
auto eth0
iface eth0 inet dhcp

# The Wifi interface
auto eth1
iface eth1 inet dhcp

iwconfig :

lo        no wireless extensions.

eth0      no wireless extensions.

eth1      RT2500 Wireless  ESSID:"WANADOO-F9A0"
          Mode:Managed  Frequency=2.412 GHz  Bit Rate:11 Mb/s   Tx-Power=-1
          RTS thr:off   Fragment thr:off
          Encryption key:off
          Link Quality=0/100  Signal level=-120 dBm  Noise level:-196 dBm
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:0   Missed beacon:0

sit0      no wireless extensions.