private void btn_adminTools_Click(object sender, RoutedEventArgs e)
        {
            // Event handler for when the user clicks the Admin Tools button
            // Opens a new AdminWindow instance and closes down this window

            AdminWindow admin_window = new AdminWindow();

            admin_window.Show();
            window_main.Close();
        }
        private void mnu_adminTools_Click(object sender, RoutedEventArgs e)
        {
            // Event handler for when the user clicks Admin Tools
            // from the File menu
            // Opens a new AdminWindow instance and closes down this window

            AdminWindow admin_window = new AdminWindow();

            admin_window.Show();
            window_main.Close();
        }