private void DetailGrid_KeyUp(object sender, KeyEventArgs e)
        {
            if (e.Key == Key.Down)
            {
                var currentRowIndex = (_viewModel.SelectedMainRow.DetailsList.IndexOf(_viewModel.SelectedDetailRow));
                if (currentRowIndex == (_viewModel.SelectedMainRow.DetailsList.Count - 2))
                {
                    _viewModel.AddNewDetailRow(true);
                }
            }
            else if (e.Key == Key.Delete)
            {
                _viewModel.SelectedDetailRows.Clear();
                foreach (var row in TblPeriodLineDataGrid.SelectedItems)
                {
                    _viewModel.SelectedDetailRows.Add(row as TblAccountIntervalViewModel);
                }

                _viewModel.DeleteDetailRow();
            }
        }