private void Selected_Click(object sender, RoutedEventArgs e)
 {
     if (PagesManager.currentState != 1)
     {
         if (Item.items != null)
         {
             if (Item.items.Count != 0)
             {
                 PagesManager.CleanFrame();
                 PagesManager.ShowSelectedTrips();
                 Back.Visibility = Visibility.Visible;
                 ChangeWindow(true);
                 System.GC.Collect();
             }
             else
             {
                 MessageBox.Show("Вы не выбрали ни одной путевки.", "", MessageBoxButton.OK, MessageBoxImage.Warning);
             }
         }
         else
         {
             MessageBox.Show("Вы не выбрали ни одной путевки.", "", MessageBoxButton.OK, MessageBoxImage.Warning);
         }
     }
 }
 private void Cabinet_Click(object sender, RoutedEventArgs e)
 {
     if (PagesManager.currentState != 2)
     {
         PagesManager.CleanFrame();
         PagesManager.ShowCabinet();
         Back.Visibility = Visibility.Visible;
         ChangeWindow(true);
         System.GC.Collect();
     }
 }
 private void Trips_Click(object sender, RoutedEventArgs e)
 {
     if (PagesManager.currentState != 0)
     {
         //clear back state
         PagesManager.CleanFrame();
         PagesManager.ShowFilterTrips();
         Back.Visibility = Visibility.Visible;
         ChangeWindow(true);
         System.GC.Collect();
     }
 }
 private void History_Click(object sender, RoutedEventArgs e)
 {
     //вывод в дата грид все путевки полученные клиентом
     if (PagesManager.currentState != 3)
     {
         PagesManager.CleanFrame();
         PagesManager.ShowHistory();
         Back.Visibility = Visibility.Visible;
         ChangeWindow(true);
         System.GC.Collect();
     }
 }