Hi, Kautav,
After delcaring the message use EXIT, and END SELECT syntex.
select bwtar bwtty from mbew into itab where matnr = lw_req_item-matnr and bwkey = lw_req_item.
check sy-subrc EQ 0.
if itab-bwtty = 'S' and itab-bwtar <> lw_req_item-bwtar.
message 'pR ' type 'E'.
endif.
endselect.
Regards,
Venkat.