;docformat='rst'
;+
;    Set the version
;
; :Author:
;    Chris Jeppensen, Bill Barrett (conversion to regular expression)
;-
function lookup_version, data_product, revision=revision
  ; The level should end in either a single digit or a single digit
  ;   followed by a letter.
  version_regex = '.*([[:digit:]]{1})([A-E])?.*'
  match = stregex(data_product, version_regex, /extract, /fold_case, /subexpr)
  ; For the regular expression above match[1] is the level number (1, 2, 3)
  ;  and match[2] is if present a qualifier such as 'A', 'B', etc.
  case fix(match[1]) of
    1: begin
      if match[2] eq 'A' then begin
        revision = !REVISION_1A
        version = !VERSION_1A
      endif else begin
        revision = !REVISION_1B
        version = !VERSION_1B
      endelse
    end
    2: begin
      revision = !REVISION_2
      version = !VERSION_2
    end
    3: begin
      revision = !REVISION_3
      version = !VERSION_3
    end
    4: begin
      revision = !REVISION_1A
      version = !CIPS_VERSION
    end
    else: print, get_routine_name() + 'Unknown data product: ' + data_product
endcase

   return, string(version,format='(f05.2)')
end