Ok here is the source that I had used.

lifehacker. com/5305094/how-to-crack-a-wi+fi-networks-wep-password-with-backtrack

And the comand lines are

airmon-ng
airmon-ng stop (interface)...

Alright, i feel that i am semi computer savy and i was sucsessful in my first attempt with BT3 but I tried agian about 3 days later and this is the issue. I check the signal strength using airodump...