(form "20200" (size 67 11)
  (heading "CLASSIFY BLOCKS")
  (label (position  2  3) (text "Attribute to classify on"))
  (label (position  2  4) (text "Attribute to store classification in"))
  (label (position  2  6) (text "Number of classifications"))
  (label (position  2  8) (text "Constrain?"))
  (field "srcatt" (position 32  3) (display_length 26) (input allowed)
    (translate lower) (null allowed) (max_length 30))
  (field "targatt" (position 32  4) (display_length 26) (input allowed)
    (translate lower) (null allowed) (max_length 30))
  (field "numgrps" (position 32  6) (display_length 16) (input allowed)
    (format integer_4) (null disallowed) (max_length 16))
  (field "constrain" (position 13  8) (display_length  1) (input allowed)
    (value_in "Y" "N")
    (default "N")
    (translate upper) (null allowed) (max_length 1))
  (default_buttons)
)