Each time I gave a new version of my project to our tester then he placed the new project within a new root folder ( a new site then ). Inside the php files there are session variables which are created and used. So the problem comes when he opens two sites at the same time to compare the two releases : with the first site he opens a page , then a session variable is created. Now he opens the second site and go to a particular page then he is directly redirected to a particular page because of the session variable from the previous site. So how to create site-independent session variables ?
Incorporate the folder name into your session variable as a prefix.
Something like:
$session_prefix = preg_replace('/[^a-z0-9]/i', '_', dirname($_SERVER['SCRIPT_NAME'])).'_';
$_SESSION[$session_prefix.'myIdentifier'] = ...
Would require a bit more logic if you run scripts which are residing in subdirectories.
So how to create site-independent session variables ?
Use different domains for your sites, not folders as you do now. Use different name (key) for your session variable.