i have push buttons on screen.when i click on push button ok_code is blank and nothing happening.
CONTROLS: tabcontrol TYPE TABLEVIEW USING SCREEN 1000.
DATA : OK_CODE type sy-ucomm,
SAVE_OK type OK_CODE,
itab like ZIB_MM_BK occurs 0 with header line.
DATA : t_code type sy-tcode.
MODULE USER_COMMAND_1000 INPUT.
SAVE_OK = OK_CODE.
clear OK_CODE.
CASE SAVE_OK.
when 'DISPLAY'.
select * from zib_mm_bk into table itab.
when 'CHANGE'.
update zib_mm_bk from table itab.
when 'CLEAR'.
clear tabcontrol.
when 'INSERT'.
insert zib_mm_bk from table itab.
when 'EXIT'.
leave screen.
exit.
ENDCASE.
ENDMODULE. " USER_COMMAND_1000 INPUT
plz give me solution its urgent.