open Tk ;;
let top = openTk () ;;
Wm.title_set top "Application 16" ;;
let v = Textvariable.create () ;;
Textvariable.set v "OFF" ;;
let b = Checkbutton.create
    ~text:"Case à cocher"
    ~variable:v
    ~onvalue:"ON" ~offvalue:"OFF"
    top ;;
let bq = Button.create
    ~text:"The end"
    ~command:(fun () ->
      Printf.printf "%s\nBye.\n" (Textvariable.get v);
      closeTk () ; exit 0)
    top ;;
pack [coe b;coe bq] ;;
let _ = Printexc.print mainLoop ();;