Sorry my code its the next:
method IF_EX_ME_PROCESS_PO_CUST~CHECK .
DATA:
v_ewaers TYPE WAERS.
IF sy-tcode = 'ME21N'.
"DATA: ls_mepoheader TYPE mepoheader.
"ls_mepoheader = im_header->get_data( ).
IMPORT v_ewaers TO v_ewaers FROM MEMORY ID 'ewaers'.
IF NOT v_ewaers IS INITIAL.
DATA: lt_fields TYPE TABLE OF sval,
lw_fields TYPE sval,
lc_return TYPE c.
CALL FUNCTION 'POPUP_GET_VALUES'
EXPORTING
* no_value_check = ‘ ‘ " Desactiva verificaciones del correspondiente tipo de datos
popup_title = 'Título (máx 60 caracteres)'
start_column = '5'
start_row = '5'
IMPORTING
returncode = lc_return
TABLES
fields = lt_fields
EXCEPTIONS
error_in_fields = 1
OTHERS = 2.
ENDIF.
ENDIF.
endmethod.