I'm trying to connect BackTrack 4 RC2 to my wireless network with the following command:

Code:
 iwconfig wlan0 essid my_network_name key My_WPA_Shared_Key
however, I keep getting this error message:

Error for wireless request "Set Encode" (8B2A): invalid argument "My_WPA_Shared_Key"
I also tried the s: option like this:

Code:
 iwconfig wlan0 essid my_network_name key s:My_WPA_Shared_Key
but I got this error message:

Error for wireless request "Set Encode" (8V2A) : SET failed on device wlan0 ; Invalid argument
The "key" I used was my passphrase which we use to access the internet (its not a hex key). The router is a Linksys WRT54G2 and its "Security Mode" is WPA Personal.

Any assistance will be greatly appreciated. Thanks in advance