PAINTSTRUCT
   Windows Structure to paint a window
------------------------------------------------------------------------------

   The PAINTSTRUCT structure ( short form : PS ) contains information for 
   an application. This information can be used to paint the client area 
   of a window owned by that application. 

   It looks like this :

     +-----------------------------------------+
     |  /* ps */                               |
     |  typedef struct tagPAINTSTRUCT {        |
     |     HDC  hdc ;                          |
     |     BOOL fErase ;                       |
     |     RECT rcPaint ;                      |
     |     BOOL fRestore ;                     |
     |     BOOL fIncUdpate ;                   |
     |     BYTE rgbReserverd[16] ;             |
     |  } PAINTSTRUCT;                         |
     +-----------------------------------------+


  DESCRIPTION:
   
   hDC          Identifies the display context to be used for painting. 
                This context is only valid within the rcPaint area !
   fErase       specifies whether the background needs to be redrawn. This 
                value is nonzero if the application should redraw the 
                background
   rcPaint      Specifies the upper-left and lower-right corners of the 
                rectangle in which the painting is requested
   fRestore     Reserved; used internally by Windows. 
   fIncUpdate   Reserved; used internally by Windows. 
   rgbReserved  reserved memory object used internally by Windows


   This Paintstructure will be automatically created by Windows every time
   that the window is painted. It is stored in tWindow:cPS