[newbie] Display - Gtk warning

[Francois Massonneau]

Hi,

When I want to run a program, this is the warning message I've (and of
course, the program doesn't fire up) :
Gtk-WARNING ** : cannot open display.
I have a Matrox Millenium II, and have no problem when running Xwindow.
What do I have to do to make it works ? Thanks. Francois