private void newItemButton_Click(object sender, RoutedEventArgs e)
        {
            if (_Model.IsRunning)
            {
                System.Windows.MessageBox.Show("Please wait for the current operation to complete.",
                                               string.Format("{0} Order Management", _Model.ServerType), MessageBoxButton.OK, MessageBoxImage.Stop);
                return;
            }
            if (FileIsNotCurrent())
            {
                return;
            }
            if (0 != _Model.CurrentParent.HeaderId)
            {
                return;
            }

            var win = new AddItemWindow();

            win._Model      = _Model;
            win.DataContext = _Model;
            win.ShowDialog();
        }
        private void newItemButton_Click(object sender, RoutedEventArgs e)
        {
            if (_Model.IsRunning)
            {
                System.Windows.MessageBox.Show("Please wait for the current operation to complete.",
                    string.Format("{0} Order Management", _Model.ServerType), MessageBoxButton.OK, MessageBoxImage.Stop);
                return;
            }
            if (FileIsNotCurrent()) return;
            if (0 != _Model.CurrentParent.HeaderId) return;

            var win = new AddItemWindow();
            win._Model = _Model;
            win.DataContext = _Model;
            win.ShowDialog();
        }