thanks everyone, the problem already solved. i put below select statement inside looping of lw_ekpo, then, append to it_output.
CLEAR lt_t007s.
SELECT mwskz text1 kalsm
INTO CORRESPONDING FIELDS OF TABLE lt_t007s
FROM t007s
WHERE mwskz = lw_ekpo-mwskz AND kalsm = 'TAXMY'.
IF sy-subrc EQ 0.
sort lt_t007s by mwskz.
ENDIF.
READ TABLE lt_t007s INTO lw_t007s with key mwskz = lw_ekpo-mwskz Binary search.
IF sy-subrc eq 0.
it_output-t007s-text1 = lw_t007s-text1.
it_output-t007s-mwskz = lw_t007s-mwskz.
it_output-t007s-kalsm = lw_t007s-kalsm.
ENDIF.
Thanks, regards
liyana