/* disallow drop events */
gtk_drag_dest_set(notebook, 0, NULL, 0, 0);
gtk_box_pack_start(GTK_BOX(vbox), notebook, TRUE, TRUE, 6);
/* disallow drop events */
gtk_drag_dest_set(notebook, 0, NULL, 0, 0);
gtk_box_pack_start(GTK_BOX(vbox), notebook, TRUE, TRUE, 6);