(form "00700" (size 75 20)
  (heading  "STRING MATHS")
  (label (position 2 3) (text     "Define the files to be processed"))
  (label (position 2 4) (text     "Location"))
  (label (position 2 5) (text     "ID range"))
  (label (position 2 7) (text     "Define the files to be created"))
  (label (position 2 8) (text     "Location"))

  (field "file_loc" (position 15 4) (display_length 32) (input allowed)
     (null allowed) (file (link "file_id") (extension "*.str"))
     (max_length 256))
  (field "file_id"  (position 15 5) (display_length 16) (input allowed)
     (format range) (null allowed)
     (max_length 256))
  (field "result_loc" (position 15 8) (display_length 32) (input allowed)
     (null allowed) 
     (max_length "FIO_MAX_LOCATION_LENGTH"))

  (scroll_block "main" (position  3  10) (size 70 9)
     (extra  0 1)
     (scroll_size 70 100)
     (repeat interactive (grow  0  1) (instances  10 (min  1) (max 100)))

    (top
      (label (position  1  0) (text     "String range"))
      (label (position 12  0) (text     "Constraint"))
      (label (position 33  0) (text     "Field"))
      (label (position 49  0) (text     "Expression"))
    )

    (main
      (field "str_range" (position 1  0) (display_length 10) (input allowed)
        (null allowed)
        (max_length 256)
      )
      (field "constraint" (position 12  0) (display_length 20) (input allowed)
        (null allowed)
        (max_length 256)
      )
      (field "field" (position 33  0) (display_length 10) (input allowed)
        (null allowed)
        (max_length 256)
      )
    (field "equals" 
        (position 46  0) 
        (display_length 1)
        (background 
            (user_option "form_background")
        )
        (input disallowed)
        (max_length 1)
        (default "=") 
    )
      (field "expr" (position 49  0) (display_length 20) (input allowed)
        (null allowed)
        (max_length 256)
      )
    )
  )

  (default_buttons)
)