oWin:QueryEndSession() -> < nResult >

------------------------------------------------------------------------------


 DESCRIPTION:

  This method responds to a WM_QUERYENDSESSION message which is sent when
  the user chooses to end the Windows session, or when an application calls 
  the ExitWindows function. It therefore calls the ::End() method.

  If < nResult > is zero, the Windows session is not ended. Windows stops 
  sending WM_QUERYENDSESSION messages as soon as one application does
  this, and sends WM_ENDSESSION messages with a FALSE as the first
  parameter to any applications that had already ended.