function sdw_getmaskim,imagename,extver

common sdwsave1, maskfile, maskext, maskeori, maskgoodval

  ; Read mask image file.
  !err = 1
  if (imagename eq 'default') then return,-1
  if maskeori eq 0 then begin
    if extver ne -1 then begin
      ua_fits_read, imagename, im, him, extver = extver, extname = maskext, $
		    /no_abort
    endif else begin
      ua_fits_read, imagename, im, him, extname = maskext, /no_abort
    endelse
    if (!err eq -1) then begin
      print,"sorry, couldn't find a corresponding data quality extension."
      return, -1
    endif else begin
      return, im
    endelse
  endif else begin
    test = findfile (maskfile, COUNT = fcount)
    if (fcount ne 0) then begin
      ua_fits_read, maskfile, im, him, /no_abort
      return, im
    endif else begin
      print,"sorry, couldn't find mask file."
      return, -1
    endelse
  endelse

end