public string SaveProps()
        {
            var props = new DateTimeColumnProperties();

            if (rdbDateOnly.Checked)
            {
                props.Format = DateTimeColumnFormat.DateOnly;
            }
            else if (rdbTimeOnly.Checked)
            {
                props.Format = DateTimeColumnFormat.TimeOnly;
            }
            else
            {
                props.Format = DateTimeColumnFormat.DateTime;
            }

            props.DateFormat = cmbDateFormat.Text;
            props.TimeFormat = cmbTimeFormat.Text;

            return(props.Save());
        }