Jason, thank you again for your reply. I attempted to follow your directions; however, my cart page does not have access restriction codes. I attempted to insert the session variable in likely places I thought may work - but to no success. When I did insert the guest session variable, a "404 - Not Found" warning appeared on the web. I have provided a copy of my cart page for your review.
You may wish to know that my checkout.php page has access restriction codes which redirects users to the login page. In my attempt to trouble shoot, I inserted the guest session variable on the checkout page just above the access restriction codes. This did not work either. I have also provided a copy of my checkout page for your convenience.
Thank you in advance for your continued assistance!