(require "Tk-classes")

(define lab  (make <Label> :text "A simple interface"))
(define box  (make <Frame> :border-width 3 :relief "ridge"))
(define l    (make <Listbox>   :parent box))
(define s    (make <Scrollbar> :parent box :orientation "vertical"))
(define quit (make <Button> :text "Quit" :command '(quit)))

;; Place the listbox and its scrollbar in "box"
(pack l :expand #t :fill "both" :side "left")
(pack s :expand #t :fill "y" :side "right")

;; place all widget on the screen
(pack lab box quit)