Example using wpa_supplicant

error0327@atomicwar:~$ su
Password:
atomicwar:/home/error0327# wpa_passphrase AtomicWar = "AP Name"
# reading passphrase from stdin
foooooooo = "the password "
network={
ssid="AtomicWar"
#psk="foooooooo"
psk=c84b80bba0f84a56a7adfc61dfc7a9e2fe5e2a7299e13c4b945ae8e298ec8f5b
}

now copy from network= to }

and past it in the file **

make a new file name it key.conf in the path /etc/wpa_supplicant/

gedit /etc/wpa_supplicant/key.conf and past **

then

wpa_supplicant -D wext -i wlan1 -c /etc/wpa_supplicant/key.conf

* wlan1 is my internet interface .

in a new window : dhclient wlan1