FUNCTION definedefaultextra, nomvariable
   case strlowcase(nomvariable) of
;       'sn':BEGIN
;          return, get_extra(min = 31., max = 37., inter = .2, lct = 33,/nocontout)
;       END
;       'tn':BEGIN
;          return, get_extra(min = 20, max = 31, inter = .5, lct = 39)
;       END
;       'un':BEGIN
;          return, get_extra(min = -1, max = 1, inter = .1, lct = 64)
;       END
;       'vn':BEGIN
;          return, get_extra(min = -1, max = 1, inter = .1, lct = 64)
;       END
      ELSE:
   ENDCASE

   return, get_extra(min = '', max = '', inter = '', lct = 39)
end