private void btnSave_Click(object sender, RoutedEventArgs e) { String companyName = tbCompanyName.Text; if (companyName.Length < 2) { throw new ApplicationException(" must be greater than 2"); } String firstName = tbFirstName.Text; String lastName = tbLastName.Text; String phoneNum = tbPhoneNum.Text; String fax = tbFax.Text; String Email = tbEmail.Text; String webSite = tbWebsite.Text; String street = tbStreet.Text; String city = tbcity.Text; String postalCode = tbPostalCode.Text; String province = tbProvince.Text; String country = tbCountry.Text; Boolean status; if (rbCustomer.IsChecked == true) { status = true; } else { status = false; } BindingExpression be = tbCompanyName.GetBindingExpression(TextBox.TextProperty); if (be.HasValidationError) { tbCompanyName.BorderBrush = Brushes.Red; } Customer newCustomer = new Customer { CompanyName = companyName, Street = street, City = city, Province = province, Postal = postalCode, Phone = phoneNum, Fax = fax, ContactFirstName = firstName, ContactLastName = lastName, Country = country, CreateDate = DateTime.Today, Status = status, Email = Email }; db.AddPerson(newCustomer); MessageBox.Show("New Customer is added", "Successfully message", MessageBoxButton.OK, MessageBoxImage.Information); var mainWin = Application.Current.Windows.Cast <Window>().FirstOrDefault(window => window is MainWindow) as MainWindow; //mainWin.btnOpportunity.Focus(); //mainWin.btnAddressBook.Focus(); this.Close(); AddressBook addressBook = new AddressBook(); //addressBook.DisplayAddressBook(); List <Customer> listCustomer = db.GetAllCustomers(); addressBook.lvAddress.Items.Clear(); foreach (Customer c in listCustomer) { addressBook.lvAddress.Items.Add(c); } mainWin.frTest.Refresh(); //MessageBox.Show("New Customer is added", "Successfully message", MessageBoxButton.OK, MessageBoxImage.Information); //AddressBook addressBook = new AddressBook(); // addressBook.DisplayAddressBook(); this.Close(); }