private void btnSave_Click(object sender, RoutedEventArgs e) { Instructor nwInstructor = new Instructor() { Address = txtAddress.Text, ContactNumber = txtPhone1.Text, DefensiveExpiry = Convert.ToDateTime(dtpDefensiveExp.SelectedDate), DefensiveNo = txtDefensive.Text, Email = txtEmail.Text, IDNumber = txtIDNumber.Text, LicenceNumber = txtLicence.Text, Name = txtName.Text, Resigned = false, Surname = txtSurname.Text }; DbInsert.InsertInstructor(nwInstructor); MessageBox.Show("Instructor Added", "NEW INSTRUCTOR", MessageBoxButton.OK, MessageBoxImage.Information); var mainWindow = Application.Current.Windows.Cast <Window>().FirstOrDefault(window => window is MainWindow) as MainWindow; InstructorDetails newInstructor = new InstructorDetails(); mainWindow.grdMain.Children.Clear(); mainWindow.grdMain.Children.Add(newInstructor); }