求如何让页签在执行后点返回按钮返回原来的执行前的页签 - abap吧

level 2

REPORT ztest_sum. 2 3 TABLES:mara. 4 *TABLES sscrfields. "引用屏幕字段属性 5 6 SELECTION-SCREEN BEGIN OF SCREEN 100 AS SUBSCREEN . "定义子屏幕100 7 SELECTION-SCREEN BEGIN OF BLOCK a1 WITH FRAME TITLE text-001. 8 SELECT-OPTIONS:mat1 FOR mara-matnr NO INTERVALS. 9 SELECTION-SCREEN SKIP 1.10 PARAMETERS: chk1 AS CHECKBOX DEFAULT 'X'.11 SELECTION-SCREEN END OF BLOCK a1.12 SELECTION-SCREEN END OF SCREEN 100.13 14 SELECTION-SCREEN BEGIN OF SCREEN 200 AS SUBSCREEN.15 PARAMETERS:mat2 LIKE mara-matnr.16 SELECTION-SCREEN END OF SCREEN 200.17 18 *定义一个TAB空间，取名MYTAB，空间高为5，共分为两个页签BUTTON1/BUTTON219 *两个页签的功能代码分别为PUSH1/PUSH220 21 SELECTION-SCREEN: BEGIN OF TABBED BLOCK mytab FOR 5 LINES,22 TAB (20) button1 USER-COMMAND push1,23 TAB (20) button2 USER-COMMAND push2,24 END OF BLOCK mytab.25 26 *为TAB控件分别初始化值，应用于TEXT ELEMENT文本27 INITIALIZATION.28 button1 = text-010.29 button2 = text-020.30 mytab-prog = sy-repid.31 mytab-dynnr = 100.32 33 AT SELECTION-SCREEN.34 CASE sy-ucomm.35 WHEN 'PUSH1'.36 mytab-dynnr = 100.37 WHEN 'PUSH2'.38 mytab-dynnr = 100.39 WHEN OTHERS.40 ENDCASE.