Execute button missing after displaying the error message on selection screen

Hi,

Execute(F8) button is missing in my program after displaying the error message in the selection screen.

AT SELECTION-SCREEN.

If field IS INITIAL.

   Message s001 display like 'E'.

   call selection-screen 1000.

endif.

i tried different combinations after the message statement in the above code.

*       Set SCREEN 0.  <== Giving error message SET SCREEN not allowed in subscreens (Screen RVV50R10C 1010)

*       LEAVE to SCREEN 1000.<= Same error message as above.

*       call SCREEN 1000.<= Giving error message Selection screen RVV50R10C 1000 was not called using CALL SELECTION-SCREEN.

*       LEAVE to LIST-PROCESSING <== Giving same error as of SET SCREEN.

*       CALL SELECTION-SCREEN 1000.  <== Execute button missing.

In the AT SELECTION-SCREEN OUTPUT we have the FM.

CALL FUNCTION 'RS_SET_SELSCREEN_STATUS'

          EXPORTING

               p_status  = sy-pfkey                           "hp_370442

               p_program = lf_program

          TABLES

               p_exclude = lt_cua_exclude.

Please let me know your inputs.

Thanks in advance.