如何灰掉工具栏上的按钮

方法：

REPORT z_barry_test_toolbar NO STANDARD PAGE HEADING .

TYPE-POOLS:slis.

DATA:rt_extab TYPE slis_t_extab.

START-OF-SELECTION.
APPEND 'TEST1' TO rt_extab.
* APPEND 'TEST2' TO rt_extab.

SET PF-STATUS 'STANDARD' EXCLUDING rt_extab.

WRITE '两个按钮，左边那个被灰掉了'.
WRITE / '虽然显示但是不可以按'.

AT USER-COMMAND.

IF sy-ucomm = 'BACK'.
LEAVE PROGRAM.
ENDIF.