private void tabControlOrganizationStructure_SelectionChanged(object sender, SelectionChangedEventArgs e)
 {
     if (e.Source is TabControl)
     {
         switch (tabControlOrganizationStructure.SelectedIndex)
         {
             case 0:
                 if (frame1 != null)
                 {
                     PageFacultyStructureMenu m_page = new PageFacultyStructureMenu();
                     frame1.Navigate(m_page);
                 }
                 break;
             case 1:
                 break;
             case 2:
                 break;
             default:
                 break;
         }
     }
 }
 private void Page_Loaded(object sender, RoutedEventArgs e)
 {
     PageFacultyStructureMenu m_PageFacultyStructureMenu = new PageFacultyStructureMenu();
     frame1.Navigate(m_PageFacultyStructureMenu);
 }