private void EditInfoItem(object sender, EventArgs e)
        {
            AdditionalInfo info = (AdditionalInfo)lbAdditionalInfo.SelectedItem;

            if (info != null)
            {
                AdditionalInfoDialog dialog = new AdditionalInfoDialog(new AdditionalInfo(info));
                dialog.ShowDialog();

                if (dialog.DialogResult == DialogResult.OK)
                {
                    if (org.AdditionalInfosToAdd.Contains(info))
                    {
                        org.AdditionalInfosToAdd.Remove(info);
                        org.AdditionalInfosToAdd.Add(dialog.AdditionalInfo);
                    }
                    else
                    {
                        org.AdditionalInfosToEdit.RemoveAll(p => p.Id == dialog.AdditionalInfo.Id);
                        org.AdditionalInfosToEdit.Add(dialog.AdditionalInfo);
                    }
                    lbAdditionalInfo.Items[lbAdditionalInfo.SelectedIndex] = dialog.AdditionalInfo;
                }
            }
        }
        private void btnAddInfo_Click(object sender, EventArgs e)
        {
            AdditionalInfoDialog dlg = new AdditionalInfoDialog();

            dlg.ShowDialog();
            if (dlg.DialogResult == DialogResult.OK)
            {
                lbAdditionalInfo.Items.Add(dlg.AdditionalInfo);
                org.AdditionalInfosToAdd.Add(dlg.AdditionalInfo);
            }
        }