What would cause a firewall not to let someone make a reservation? It fails security.
Without getting too technical, in a nutshell, the firewall security somehow modifies the HTTP_REFERER variable that is sent to the uReserve script (behind the scenes) from the reservation form page. uReserve thinks the reservation form is being posted from somewhere outside of the primary domain (from an HTTP_REFERER that it does not expect), such as from a hacker's computer (which is likely not the case here - it is not like they are breaking into Fort Knox).
If you are hearing reports of an "Illegal Referrer" error when trying to place a reservation, and your site is behind a firewall, perhaps you just want to disable the check in the script, using the following instructions:
INSTRUCTIONS TO DISABLE THE REFERRER CHECK IN URESERVE 2.0
STEP 1: Make a backup of your current ureserve.pl script...just in case.
STEP 2: Open your ureserve.pl script with any text editor such as WordPad.
STEP 3: Do a "search" in script for the line that starts with the following
&missing_input("Illegal Referrer Page"
(There is only one occurance of that line).
STEP 4: Comment that line out by adding a "#" sign in front of it, like
#&missing_input("Illegal Referrer Page"
STEP 5: Save the script (as TEXT if your editor asks)... and try it out!
I will try that. It is actually 1 user that has his pc behind a firewall and has asked me " what program or application do I need let through my firewall, when I try to make a reservation it fails security "