Aloaha !!!

A friend of mine recomended me GTK-Gnutella "This stuff roxx" He said...
So I type "emerge net-p2p/gtk-gnutella" (I use Gentoo)

Well it installed and then...... nothing ?
First I get an error saying I cant use as root ??? Who cares it runs as root ????
Anyway, I go like su - jessy, and then I get :

-----<CUT>-----
jessy@jcpd jessy $ gtk-gnutella
Xlib: connection to ":0.0" refused by server
Xlib: No protocol specified


Gtk-WARNING **: cannot open display: :0.0
jessy@jcpd jessy $
-----<CUT>-----

What the f* ehhr ahum ahum, what is that ??

Wheeeee :'-( why cant I just run the program... Now I have to use that stupid Windows again with WinMX :'-(

Can anyone hellep meeee?????


Greets

Jessy