void RelatedColumnsList_SelectedIndexChanged(object sender, EventArgs e)
{
ListAggregationList.ClearSelection();
FormatList.ClearSelection();
Field.Aggregation = AggregationList.SelectedValue;
AggregationList.ClearSelection();
Field.ListAttributeAggregation.ColumnName = RelatedColumnsList.SelectedValue;
Field.ListAttributeAggregation.AggregateLexem = string.Empty;
// ListAggregationList.DataBind();
// FormatList.DataBind();
}