Running just 'iwconfig' after the initial iwconfig setup command should show your essid and key etc. If so, then it's associated ok. After that you'll have to run a program to actually do the dhcp setup, I don't know what the dhcp client is called on the 770, try just entering 'dhcp' and press <tab>. It's usually either of dhcp-client or dhcpcd, but could be something else. In any case, whatever its name run it with 'wlan0' as argument (e.g. 'dhcp-client wlan0')