globals [name]

to go
  ;; user-input lets the user type in a string
  if name = 0.0    ;; has name been set yet?
    [ set name user-input "What is your name?" ]

  ;; read-from-string will convert a string into a number
  let num read-from-string
            user-input "How many turtles would you like?"

  ;; user-choice gives the user a set of choices
  ;; runresult runs a NetLogo reporter held in a string
  let col runresult
            user-one-of "What color should the turtles be?"
                        ["red + 1" "blue - 2" "green + 3"]

  ;; make the turtles
  create-turtles num
    [ set color col
      fd random-float max-pxcor ]

  display

  ;; user-message tells the user something
  user-message (word "OK, " name ", there are "
                     count turtles " turtles now.")

  ;; user-yes-or-no? asks the user a yes-or-no question
  if not user-yes-or-no? "Would you like more turtles?"
    [ stop ]
end


; Public Domain:
; To the extent possible under law, Uri Wilensky has waived all
; copyright and related or neighboring rights to this model.