private void radarFirstClick(object sender, RoutedEventArgs e)
 {
     if (radarFirstp == null)
     {
         RadarFirstPage p = new RadarFirstPage();
         radarFirstp = p;
     }
     content.Content = radarFirstp;
     CurrentControl  = content;
 }
        private void radarFirstClick(object sender, RoutedEventArgs e)
        {
            RadarFirstPage p = new RadarFirstPage();

            content.Content = p;
        }