Screen Design Complications

Question

Hi,
Iam working on screen desiging since last one week.
Unlike VB it is not so user friendly.
I want best source of examples and more stuff on screen designing. The best and more and more examples on each screen design element. The events to be triggered on selecting a particualr screen element etc...
please arrange the best and more and more examples to understand and develop self -explanatory topics on screen designing

Answer 1

MPP Action Events
    When ever acction is performed on Screen raises PAI event and We can handle where action events related Code Functionality.
PBO ( Process Before Output )
   This event is similer to Initialization of Selection-Screen.
    This event used In mpp to Add Title Bar,
Menu Bar for the screen. Default Properties of the screen can be loaded.
   This event is fired when Screen is Loading for the first Time, and when ever action is Perfomed on the screen.
  When ever PAI is called ,  the event reloads the screen, hence PBO will be called automatically.
  IF the select statement is used in PBO, see that  statement is declared in a conditional statement. Else the statement is executed for number of times when ever we load the screen and action is performed.
example code:
1) Top include file.
   data : okcode like sy-ucomm,
             a type i.
2) PBO and PAI code.
MODULE STATUS_0101 OUTPUT.
if a = 0.
   MESSAGE S000(ZMSGCLS).
   a = 1.
endif.
ENDMODULE.
MODULE USER_COMMAND_0101 INPUT.
  CASE OKCODE.
     WHEN 'RAISE'.
     WHEN 'EXIT'.
       LEAVE PROGRAM.
  ENDCASE.