Thanks djohnston, yes it's working but i still don't know if it's possible to save the configuration for further use. Is there a file or something that can be saved and re-used later on ?
Here's the deal. You have two ways to connect to the internet using your laptop. You can connect by plugging in an ethernet cable like you're doing now. You can also connect to a wireless router or access point if the ethernet is unplugged. You don't really need both ways at the same time. Once each device is set up, you can switch between them using your network icon. The devices are probably ath0 (wireless) and eth0 (wired). You should have hotplugging enabled in the networking setup wherever it's an option. It's a pretty simple task to switch between even different wireless networks, as long as you can gain access. In other words, some networks will require a user name and password in order to connect.
I'm guessing, again, because you haven't provided a whole lot of details about how and where you're trying to use the wireless. I'm guessing you want to take the laptop to work and/or home and be able to connect to a wireless network. If you can set your wireless connection up and connect, then you can easily do it again from the desktop.