To book a special rate with United Airlines: Click Here - then go through the entire booking process online you will then find a box to add Promo Code: ZFT7436800. Or you can Click Here to fill out the form attached and National Travel Systems will be happy to assist in booking a flight for you at a discounted rate along with car rentals. If you have any questions please contact National Travel Systems. Click Here to view contact information for National Travel Systems.