public ActionResult Edit(Guid id)
        {
            AnnouncementView announcement = GetAnnouncement(id);

            var model = new AnnouncementEditModel
                            {
                                Abstract = announcement.Abstract,
                                Contact = announcement.Contact,
                                CurrentUrl = announcement.Url,
                                DisplayOnMainMenu = announcement.DisplayOnMainMenu,
                                DisplayOnSideMenu = announcement.DisplayOnSideMenu,
                                ExpiryDate = announcement.ExpiryDate,
                                IsActive = announcement.IsActive,
                                Organizer = announcement.Organizer,
                                SortOrder = announcement.SortOrder,
                                StartingDate = announcement.StartingDate,
                                StartingTime = announcement.StartingTime,
                                Text = announcement.Text,
                                Title = announcement.Title,
                                Venue = announcement.Venue
                            };
            return View(model);
        }
        public ActionResult Edit(Guid id, AnnouncementEditModel model)
        {
            SiteMapItem currentNode = GetSiteMapItem(id);
            if (!ModelState.IsValid)
            {
                model.CurrentUrl = currentNode.Url;
                return View(model);
            }

            string announcementUrl =
                BusinessShell.RunWithResult(
                    () => new UpdateAnnouncementOperation(model.Contact, model.DisplayOnMainMenu,
                                                          model.DisplayOnSideMenu, User.Identity.Name, model.ExpiryDate, id,
                                                          model.IsActive, model.Organizer, model.SortOrder,
                                                          model.StartingDate, model.StartingTime, model.Abstract, model.Text,
                                                          model.Title, model.Venue));
            return Redirect(announcementUrl);
        }