[system-tools] How to add a network interface under gnome?

[Joe Dunsmore <duns0014 umn edu>]

I have a question about the network-admin program. I'm using it under 
gnome2.10 on ubuntu and there's no button to let me add a network 
interface.  In fact, the buttons to activate or deactivate other 
interfaces are greyed out.  Does anyone have any idea what is wrong? 
How can I add a network interface? thanks.