data: c type cursor,
      wa type sbook.

open cursor c for
     select carrid connid fldate bookid smoker
     from   sbook
     where carrid = 'LH'
     order by carrid connid fldate smoker bookid.

 fetch next cursor c into corresponding fields of wa.

 while sy-subrc = 0.
   if  wa-smoker = ' '.       ==> '  ' 의 의미는 null값인가요?
     perform nonsmoker using c.
    
   elseif  wa-smoker = 'X'.
     perform smoker using c.
     skip.
    
   else.
     exit.
  

endif.
  
  endwhile.
 

  form nonsmoker using n_cur type cursor.
   while wa-smoker = ' ' and sy-subrc = 0.
     format color = 5.
      write: / wa-carrid, wa-connid, wa-fldate, wa-bookid.
      fetch next cursor n_cur into corresponding fields of wa.
  endwhile.
  endform.

  form smoker using s_cur type cursor.
   while wa-smoker = 'X' and sy-subrc = 0.
     format color = 6.
     write: / wa-carrid, wa-connid, wa-fldate, wa-bookid.
     fetch next cursor s_cur into corresponding fields of wa.
   endwhile.
  endform.