private void btnAdd_Click(object sender, EventArgs e)
        {
            CustomerCounty _newRecord = new CustomerCounty();

            _newRecord.CustomerId        = this.CustomerId;
            _newRecord.CountyCode        = (int)cboCountys.SelectedValue;
            _newRecord.CountyDescription = cboCountys.Text;
            _db.AddToCounties(_newRecord);
            _db.SaveChanges();
            this.Close();
        }