window fullscreen function does't work

[Sagar Shah <sagars dpsl net>]

Hi,
        I am working on gtkmm-2.2.3 ( Red Hat Linux 7.3 ). I want to
make window fullscreen. For that I have written one small code,

        Gtk::Window* window = manage ( new class Gtk::Window() )
        window->fullscreen();
        window->show();

But it shows, small wandow. "fullscreen" function doesn't work.
Does anyone tell me, "fullscreen" function is implemented or not in
gtkmm-2.2.3?
Or any modifications im my code?

Regards
Sagar Shah