Add Toolbar Button on Selection Screen

REPORT  ZRRSAMPLE.

TABLES: sscrfields.

DATA: d_butt1(4).

PARAMETERS: p_grpa1(10) MODIF ID a,
            p_grpa2(10) MODIF ID a,
            p_grpb1(10) MODIF ID b.

SELECTION-SCREEN FUNCTION KEY 1.
SELECTION-SCREEN FUNCTION KEY 2.

INITIALIZATION.

  MOVE 'This is button 1' TO sscrfields-functxt_01.
  MOVE 'Toggle 1'         TO sscrfields-functxt_02.

  d_butt1 = 'NO'.

AT SELECTION-SCREEN.
  IF sy-ucomm = 'FC01'.

    d_butt1          = 'YES'.
    sscrfields-ucomm = 'ONLI'.

  ELSEIF sy-ucomm = 'FC02'.

    IF sscrfields-functxt_02 = 'Toggle 1'.

      sscrfields-functxt_02  = 'Toggle 2'.

    ELSE.

      sscrfields-functxt_02  = 'Toggle 1'.

    ENDIF.

  ENDIF.

START-OF-SELECTION.

  WRITE d_butt1.