ABAP - Listbox With Values From Table

report ztest .
TYPE-POOLS : vrm.
TABLES:vbak,vbap.

DATA : v(80) TYPE c.

DATA: wa_vbak TYPE vbak,
it_vbak TYPE vbak OCCURS 0 WITH HEADER LINE,
wa_vbap TYPE vbap,
it_vbap TYPE vbap OCCURS 0 WITH HEADER LINE.

DATA: l_name TYPE vrm_id,
li_list TYPE vrm_values ,
v_count TYPE i,
l_value LIKE LINE OF li_list.

PARAMETERS: p_test(20) AS LISTBOX VISIBLE LENGTH 60 MODIF ID DAT.

INITIALIZATION.

AT SELECTION-SCREEN OUTPUT.

PERFORM get_data.
LOOP AT it_vbak.
l_value-key = it_vbak-vbeln .
l_value-text = it_vbak-vbeln .
APPEND l_value TO li_list.
ENDLOOP.

CALL FUNCTION 'VRM_SET_VALUES'
EXPORTING
id = 'P_TEST'
values = li_list
EXCEPTIONS
id_illegal_name = 1
OTHERS = 2.

AT SELECTION-SCREEN ON P_TEST.
clear : li_list , li_list[].

SELECT vbeln
matnr
meins
FROM vbap
INTO CORRESPONDING FIELDS OF TABLE it_vbap
WHERE vbeln = p_test.

START-OF-SELECTION.

SELECT vbeln
matnr
meins
FROM vbap
INTO CORRESPONDING FIELDS OF TABLE it_vbap
WHERE vbeln = p_test.

LOOP AT it_vbap.
WRITE :/ it_vbap-vbeln, it_vbap-matnr,it_vbap-meins.
ENDLOOP.

*&---------------------------------------------------------------------*
*& Form get_Data
*&---------------------------------------------------------------------*
* text
*----------------------------------------------------------------------*
FORM get_data .
SELECT vbeln
FROM vbak
INTO CORRESPONDING FIELDS OF TABLE it_vbak.
ENDFORM. " get_Data