FUNCTION changeread, newread
;
@common
;
;
; newread must be two structures
;
   if size(newread, /type) NE 8 then return, 0
;
; we compare the two structure which caracterise the read  
;
   case 1 of
      ccreadparameters.funclec_name NE newread.funclec_name:
      ccreadparameters.jpidta NE newread.jpidta:
      ccreadparameters.jpjdta NE newread.jpjdta:
      ccreadparameters.jpkdta NE newread.jpkdta:
      ccreadparameters.ixmindta NE newread.ixmindta:
      ccreadparameters.ixmaxdta NE newread.ixmaxdta:
      ccreadparameters.iymindta NE newread.iymindta:
      ccreadparameters.iymaxdta NE newread.iymaxdta:
      ccreadparameters.izmindta NE newread.izmindta:
      ccreadparameters.izmaxdta NE newread.izmaxdta:
      ELSE:return, 0
   endcase
;
; update the common paramaters
;
   ccreadparameters = newread
   jpidta = newread.jpidta
   jpjdta = newread.jpjdta
   jpkdta = newread.jpkdta
   ixmindta = newread.ixmindta
   ixmaxdta = newread.ixmaxdta
   iymindta = newread.iymindta
   iymaxdta = newread.iymaxdta
   izmindta = newread.izmindta
   izmaxdta = newread.izmaxdta
;
   return, 1
end