private void CmbSegment_SelectedIndexChanged(object sender, EventArgs e)
        {
            lstSegColumns.Items.Clear();
            string segmentCol = cmbSegment.SelectedItem as string;

            HL7Parser.Version ver = cmbHL7Versions.SelectedItem as HL7Parser.Version;
            Segment[]         seg = _repo.GetSegmentBy(ver.Name, segmentCol);
            foreach (Segment s in seg)
            {
                lstSegColumns.Items.Add(s.Name);
            }
        }
        void LoadSegments()
        {
            HL7Parser.Version ver = cmbHL7Versions.SelectedItem as HL7Parser.Version;
            MessageType       mt  = cmbMessageType.SelectedItem as MessageType;
            EventType         et  = cmbEventType.SelectedItem as EventType;

            List <TriggerEvent> _selectedEvents = _triggerEvents.Where(x => x.Version == ver.Name && x.MessageType == mt.MessageType1 && x.EventType == et.EventType1).ToList();

            foreach (TriggerEvent tr in _selectedEvents)
            {
                cmbSegment.Items.Add(tr.Segment);
            }


            if (cmbSegment.Items.Count > 0)
            {
                cmbSegment.SelectedIndex = 0;
            }
        }