void Application_SlideShowEnd(PowerPoint.Presentation Pres )
 {
     Pres.Close();
 }
 /// <summary>
 /// A PowerPoint presentation to close
 /// </summary>
 /// <param name="presentationToClose">Presentation to close</param>
 public void ClosePresentation(PPT.Presentation presentationToClose)
 {
     presentationToClose.Close();
 }