import gtk

w1 = gtk.Window()
w1.set_type_hint(gtk.gdk.WINDOW_TYPE_HINT_DIALOG)
w1.set_modal(True)
w1.show_all()

w2 = gtk.Window()
w2.set_type_hint(gtk.gdk.WINDOW_TYPE_HINT_DIALOG)
w2.set_modal(True)
w2.set_transient_for (w1)
w2.show_all()

w3 = gtk.Window()
w3.set_type_hint(gtk.gdk.WINDOW_TYPE_HINT_DIALOG)
w3.set_modal(True)
w3.set_transient_for (w2)
w3.show_all()

w1.set_transient_for(w3)

gtk.main()


