FUNCTION scan_grib_code, num, recstart
;
  nrec =  n_elements(recstart)
  codes = bytarr(nrec)
;
  FOR i = 0L,nrec-1 DO BEGIN
    offset = recstart[i]
    a = assoc(num, bytarr(1, /nozero), offset+8+9-1)
    codes[i] = a[0]
  ENDFOR
;
  RETURN, codes
END