A demo program to create subscreen in your ABAP Program

report  zsub_screen.

TABLES: USR02,       "Logon data
        SSCRFIELDS.  "FIELDS ON SELECTION SCREENS
*---------------------------------------------------------------
* SUBSCREEN 1
*---------------------------------------------------------------
SELECTION-SCREEN BEGIN OF SCREEN 100 AS SUBSCREEN.
SELECTION-SCREEN BEGIN OF BLOCK B1 WITH FRAME TITLE TEXT-010.
   SELECT-OPTIONS: USERNAME FOR USR02-BNAME.
SELECTION-SCREEN END OF BLOCK B1.
SELECTION-SCREEN END OF SCREEN 100.

*---------------------------------------------------------------
* SUBSCREEN 2
*---------------------------------------------------------------
SELECTION-SCREEN BEGIN OF SCREEN 200 AS SUBSCREEN.
SELECTION-SCREEN BEGIN OF BLOCK B2 WITH FRAME TITLE TEXT-020.
   SELECT-OPTIONS: LASTLOGI FOR USR02-TRDAT.
SELECTION-SCREEN END OF BLOCK B2.
SELECTION-SCREEN END OF SCREEN 200.

*---------------------------------------------------------------
* SUBSCREEN 3
*---------------------------------------------------------------
SELECTION-SCREEN BEGIN OF SCREEN 300 AS SUBSCREEN.
SELECTION-SCREEN BEGIN OF BLOCK B3 WITH FRAME TITLE TEXT-030.
   SELECT-OPTIONS: CLASSTYP FOR USR02-CLASS.
SELECTION-SCREEN END OF BLOCK B3.
SELECTION-SCREEN END OF SCREEN 300.

* STANDARD SELECTION SCREEN FOR SCROLLING LEFT AND RIGHT
SELECTION-SCREEN: FUNCTION KEY 1,
                  FUNCTION KEY 2.

SELECTION-SCREEN: BEGIN OF TABBED BLOCK SUB FOR 15 LINES,
                  END OF BLOCK SUB.

START-OF-SELECTION.
    SELECT * FROM USR02 WHERE BNAME IN USERNAME
                          AND ERDAT IN LASTLOGI
                          AND CLASS IN CLASSTYP.
       WRITE: / 'User ', USR02-BNAME,
                'Last Login Date ', USR02-TRDAT,
                'Last Login Time ', USR02-LTIME,
                'CLASS ', USR02-CLASS.
    ENDSELECT.
END-OF-SELECTION.

INITIALIZATION.
* SCREEN ICON LEFT AND RIGHT
  SSCRFIELDS-FUNCTXT_01 = '@0D@'.
  SSCRFIELDS-FUNCTXT_02 = '@0E@'.
  SUB-PROG = SY-REPID.
  SUB-DYNNR = 100.

AT SELECTION-SCREEN.
  CASE SY-DYNNR.

    WHEN 100.
      IF SSCRFIELDS-UCOMM = 'FC01'.
        SUB-DYNNR = 300.
      ELSEIF SSCRFIELDS-UCOMM = 'FC02'.
        SUB-DYNNR = 200.
      ENDIF.

    WHEN 200.
      IF SSCRFIELDS-UCOMM = 'FC01'.
        SUB-DYNNR = 100.
      ELSEIF SSCRFIELDS-UCOMM = 'FC02'.
        SUB-DYNNR = 300.
      ENDIF.

    WHEN 300.
      IF SSCRFIELDS-UCOMM = 'FC01'.
        SUB-DYNNR = 200.
      ELSEIF SSCRFIELDS-UCOMM = 'FC02'.
        SUB-DYNNR = 100.
      ENDIF.
  ENDCASE.