public ActionResult Commit(ViewCalendarItem item)
		{
			// get RegistrationTerm from RegistrationTermID
			RegistrationTerm term = session.Get<RegistrationTerm>(item.RegistrationTermID);
			item.RegistrationTerm = term;
			
			session.SaveOrUpdate(item.ToCalendarItem());
			TempData["message"] = String.Format("Calendar item '{0}' saved.", item.ID);
			return RedirectToAction("Index", new { id = item.RegistrationTerm.ID});
		}
		public ActionResult Edit(int id)
		{
			CalendarItem item = session.Get<CalendarItem>(id);
			
			if (item == null) {
				return RedirectToAction("Index");
			}
			else {
				ViewCalendarItem viewItem = new ViewCalendarItem(item);
				return View (viewItem);
			}
		}