Dropdown List Example in ABAP

REPORT  ZDROPDOWNLIST .

types: begin of t_vbap,
  posnr type vbap-posnr,
  end of t_vbap.

data: it_vbap TYPE STANDARD TABLE OF t_vbap,
      wa_vbap like line of it_vbap.

TYPE-POOLS: VRM.
DATA: NAME  TYPE VRM_ID,
      LIST  TYPE VRM_VALUES,
      VALUE LIKE LINE OF LIST.
""""""""""""
PARAMETERS: SO_NUM like vbap-vbeln.
""""""""""""

PARAMETERS: P_POSNR(10) AS LISTBOX VISIBLE LENGTH 10.

*********************************************************
*AT SELECTION-SCREEN OUTPUT.
AT SELECTION-SCREEN OUTPUT.

clear list.
 SELECT posnr
   up to 10 rows
   into CORRESPONDING FIELDS OF TABLE it_vbap
   from vbap
   where
   vbeln = SO_NUM.

  loop at it_vbap into wa_vbap.
    VALUE-KEY =  wa_vbap-posnr.
    VALUE-TEXT = wa_vbap-posnr.
    APPEND VALUE TO LIST.
  endloop.

  NAME = 'P_POSNR'.
  CALL FUNCTION 'VRM_SET_VALUES'
    EXPORTING
      ID     = NAME
      VALUES = LIST.


*clear list.
********************************************************
*START-OF-SELECTION.
START-OF-SELECTION.
  WRITE: / 'SELECTED VALUE KEY:', SO_NUM.

Dropdown List Example in ABAP

REPORT  ZDROPDOWNLIST .

types: begin of t_vbap,
  posnr type vbap-posnr,
  end of t_vbap.

data: it_vbap TYPE STANDARD TABLE OF t_vbap,
      wa_vbap like line of it_vbap.

TYPE-POOLS: VRM.
DATA: NAME  TYPE VRM_ID,
      LIST  TYPE VRM_VALUES,
      VALUE LIKE LINE OF LIST.
""""""""""""
PARAMETERS: SO_NUM like vbap-vbeln.
""""""""""""

PARAMETERS: P_POSNR(10) AS LISTBOX VISIBLE LENGTH 10.

*********************************************************
*AT SELECTION-SCREEN OUTPUT.
AT SELECTION-SCREEN OUTPUT.

clear list.
 SELECT posnr
   up to 10 rows
   into CORRESPONDING FIELDS OF TABLE it_vbap
   from vbap
   where
   vbeln = SO_NUM.

  loop at it_vbap into wa_vbap.
    VALUE-KEY =  wa_vbap-posnr.
    VALUE-TEXT = wa_vbap-posnr.
    APPEND VALUE TO LIST.
  endloop.

  NAME = 'P_POSNR'.
  CALL FUNCTION 'VRM_SET_VALUES'
    EXPORTING
      ID     = NAME
      VALUES = LIST.


*clear list.
********************************************************
*START-OF-SELECTION.
START-OF-SELECTION.
  WRITE: / 'SELECTED VALUE KEY:', SO_NUM.

Double clicking example in abap

REPORT  ZDOUBLECLICK .

START- OF-SELECTION.
  WRITE 'Click me'.
  AT LINE-SELECTION.
  WRITE 'Hello'. 

How to Create POP-UP window

REPORT  ZPOPUPWINDOW .

START- OF-SELECTION.
    WRITE / 'Click me' HOTSPOT ON.
AT LINE-SELECTION.
  WINDOW STARTING AT 20 20
          ENDING   AT 60 30.

   WRITE / 'hello ' HOTSPOT ON.

How to get list of active user logged on to the system with terminal and other details

Use the T-code SE37 and execute the function module TH_DISPLAY_USER_LIST.

Here you wil get the list of active users with information like Client, Terminal, Transaction code the user is working on, number of sessions opened by that user and whether Trace is ON or OFF. 

This information can be used for sort of troubleshooting purpose. 

Difference between T-Code SE09, SE10 and SE01

SE09 is the transaction code for workbench organizer. Workbench organizer is the set of utilities for development change management. All Development changes are tracked via Workbench organizer.

SE10 is for Customizing organizer. Customizing organizer is the set of tools for customizing change management. All customizing changes are tracked via customizing organizer.

SE01 is the main screen of the Change and transport Organizer. From here the administrator can achieve all tasks related to transport requests - such as create, change, view logs, display client/delivery transports, etc. SE09 and SE10 can also be accessed from here. However, not all developers might be granted access to this transaction.