notebook =
let notebook = GPack.notebook ~tab_pos:`TOP ~packing ~show_border:false ~show_tabs:false () in
let _ = (* "on" pixmap widget *)
GMisc.pixmap
off_pixmap
~packing:(fun widget -> ignore (notebook#insert_page ~pos:0 widget))
() in
let _ = (* "on" pixmap widget *)
GMisc.pixmap
on_pixmap
~packing:(fun widget -> ignore (notebook#insert_page ~pos:1 widget))
() in
notebook