How to create a toolbar in the selection screen, similar to the one below. Refer the sample code

TABLES: sscrfields.
SELECTION-SCREEN FUNCTION KEY 1.

INITIALIZATION.
sscrfields-functxt_01 = 'Tool bar www.erpdb.info'.

SELECTION-SCREEN BEGIN OF BLOCK b1 WITH FRAME TITLE text-000.
PARAMETERS: vbeln LIKE vbak-vbeln.
SELECTION-SCREEN END OF BLOCK b1.

AT SELECTION-SCREEN.
  IF sy-ucomm EQ 'FC01'.
    PERFORM toolbar_test.
  ENDIF.

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