child window

["Massimo" <max_f abaconet it>]

Hi,
I have used  "MIT-SHM" library for manipulate image, then I would have a
window created with GTK
(like : main_window = gtk_window_new (GTK_WINDOW_TOPLEVEL);)for user
interface with button and other tool and under this window I would create an
child window with:
window=XCreateWindow(display,win,0,0,width, height,0, depth,InputOutput,
visual, 0, NULL);

>From first GTK-window where can I take information for child window?

Thanks.