🕸Fergus Duniho wrote on Wed, Apr 25, 2012 03:38 PM UTC:
The problem seems to have been caused by including session_start() in the
header part of the file (not to be confused with the HTML file called
header.php). Instead of taking that code out, I have enclosed it in a
conditional that checks whether the cookie is set and runs the code only if
the cookie is not set. Anytime you go back to the page with the back
button, the cookie should already be set, and it won't need to use
session_start() to get the value the cookie should be set to.