;; A scale widget with options

(define (display-value n)
  (format #t "Flow 1 = ~A\n" n))

(scale '.s1 :label "Flow 1" :from -1000 :to 1000 :orient "horizontal" 
            :command "display-value")
(pack .s1)

;; We could avoid the display-value definition by doing
(scale '.s2 :label "Flow 2" :from -1000 :to 1000 :orient "horizontal" 
       :command "format #t \"Flow 2 = ~A~%\" ")
(pack .s2)
;; but this is probably less clear. Isn't is?