private void doctorBtn_Click(object sender, RoutedEventArgs e)
 {
     //DentistForm df = new DentistForm();
     DentistList df = new DentistList();
     df.ShowDialog();
 }
 private void Dentist_Click(object sender, RoutedEventArgs e)
 {
     DentistList f = new DentistList();
     f.ShowDialog();
 }