private void btnAddPatient_Click(object sender, RoutedEventArgs e)
        {
            WpfWebClient.ServiceReferenceEHEC.ServiceClient client = new WpfWebClient.ServiceReferenceEHEC.ServiceClient();

            Person p = new Person();

            if (ComboBoxSalutations.SelectedValue != null && ComboBoxSalutations.SelectedValue is Salutation)
            {
                if (ComboBoxGenders.SelectedValue != null && ComboBoxGenders.SelectedValue is Gender)
                {
                    if (ComboBoxCities.SelectedValue != null && ComboBoxCities.SelectedValue is City)
                    {
                        // Pick all selected fields and send object to client
                        p.Salutation = (Salutation)ComboBoxSalutations.SelectedValue;
                    }
                }
            }
            p.Gender       = (Gender)ComboBoxGenders.SelectedValue;
            p.LastName     = txtLastName.Text;
            p.FirstName    = txtFirstName.Text;
            p.StreetName   = txtStreetName.Text;
            p.StreetNumber = txtHouseNumber.Text;
            p.City         = (City)ComboBoxCities.SelectedValue;

            client.WritePatient(p);

            // Show success msgbox
            System.Windows.MessageBox.Show("Success", "INFO", MessageBoxButton.OK, MessageBoxImage.Information);

            client.Close();
        }