pop up message yes / no in ABAP

REPORT zpopup_menu_yesno. 

DATA : ld_answer TYPE string.

CALL FUNCTION 'POPUP_CONTINUE_YES_NO'

EXPORTING

textline1 = 'POPUP MENU'
textline2 = 'Yes or No?!'
titel     = 'Change Confirmation'

IMPORTING

answer    = ld_answer.
IF ld_answer = 'J'.
WRITE : / 'Yes !'.
ELSE.
WRITE : / 'Oh, No !'.
ENDIF.