private async void SubmitBarBtn_Click(object sender, RoutedEventArgs e) { Contact c = new Contact(); //validate FirstName is empty if (String.IsNullOrEmpty(ConFNameTxtBox.Text)) { MessageDialog md = new MessageDialog("Please write Name in field", "Wrong Name"); await md.ShowAsync(); ConFNameTxtBox.Focus(FocusState.Programmatic); ConFNameTxtBox.SelectAll(); return; } else { c.FirstName = ConFNameTxtBox.Text; } //validate LastName is empty if (String.IsNullOrEmpty(ConLNameTxtBox.Text)) { MessageDialog md = new MessageDialog("Please write Name in field", "Wrong Name"); await md.ShowAsync(); ConLNameTxtBox.Focus(FocusState.Programmatic); ConLNameTxtBox.SelectAll(); return; } else { c.LastName = ConLNameTxtBox.Text; } //validate CompanyName is empty if (String.IsNullOrEmpty(ConCompNameTxtBox.Text)) { MessageDialog md = new MessageDialog("Please write Name in field", "Wrong Company Name"); await md.ShowAsync(); ConCompNameTxtBox.Focus(FocusState.Programmatic); ConCompNameTxtBox.SelectAll(); return; } else { c.CompanyName = ConCompNameTxtBox.Text; } //validate Mobile number is empty if (String.IsNullOrEmpty(MobNoTxtBox.Text)) { MessageDialog md = new MessageDialog("Please write Mobile Number in field", "Wrong Mobile Number"); await md.ShowAsync(); MobNoTxtBox.Focus(FocusState.Programmatic); MobNoTxtBox.SelectAll(); return; } else { c.MobilePhone = MobNoTxtBox.Text; } viewModel.AddNewContact(c); Frame.Navigate(typeof(ContactPage)); }