public void actDelete(contact customer)
        {
            DeleteCustomerViewModel deleteCustomerViewModel = new DeleteCustomerViewModel(customer);
            DeleteCustomerView deleteCustomerView = new DeleteCustomerView(customer);

            deleteCustomerView.DataContext = deleteCustomerViewModel;
            deleteCustomerViewModel.CloseActionDelete = new Action(() => deleteCallback(deleteCustomerView,customer));

            deleteCustomerView.ShowDialog();
        }
 private void deleteCallback(DeleteCustomerView view, contact customer)
 {
     view.Close();
     customers.Remove(customer);
     NotifyPropertyChanged("customers");
 }