(form "00253" (size 33  8)
  (help "00253_TIP_0")
  (heading "VARIOGRAM MODELLING")
  (label (position  2  3) (text "Model type"))
  (label (position  2  4) (text "Nugget (Co)"))
  (label (position  2  5) (text "C"))
  (label (position  2  6) (text "Range (A)"))
  (field "model" (position 15  3) (display_length  3) (input disallowed))
  (field "co" (position 15  4) (display_length 10) (input allowed)
    (translate upper) (format real_8) (null disallowed) (max_length 10))
  (field "c" (position 15  5) (display_length 10) (input allowed)
    (translate upper) (format real_8) (null disallowed) (max_length 10))
  (field "a" (position 15  6) (display_length 14) (input allowed)
    (translate upper) (format real_8) (null disallowed) (max_length 14))
  (default_buttons)
)