/// <summary>
        ///  Running aggregations
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void btnRunAgrr_Click(object sender, EventArgs e)
        {
            try
            {
                //TODO: validation  (eg: Sum is not applicable to 'name' field)
                DTO.Aggregations aggFilter = new DTO.Aggregations();
                aggFilter.Field           = cboQryField.Text;
                aggFilter.AggregationType = cboQryAggrType.Text;

                FillAggregationListView(_customerBll.GetAggregations(aggFilter), lvwHits4);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message, "Error", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
            }
        }