gtk_box_pack_start(GTK_BOX(vbox), menu, FALSE, TRUE, 0);
gtk_box_pack_start(GTK_BOX(vbox), GTK_WIDGET(viewer), TRUE, TRUE, 0);
gtk_box_pack_start(GTK_BOX(vbox), notebook, FALSE, TRUE, 0);
gtk_box_pack_start(GTK_BOX(vbox), menu, FALSE, TRUE, 0);
gtk_box_pack_start(GTK_BOX(vbox), GTK_WIDGET(viewer), TRUE, TRUE, 0);
gtk_box_pack_start(GTK_BOX(vbox), notebook, FALSE, TRUE, 0);