I have tried to share my experience over a problem related to sessions but was unable to submit as the SPAM question is really very confusing. So I am just submitting it here:- Warning: Unknown: Your script possibly relies on a session side-effect which existed until PHP 4.2.3. Please be advised that the session extension does not consider global variables as a source of data, unless register_globals is enabled. You can disable this functionality and this warning by setting session.bug_compat_42 or session.bug_compat_warn to off, respectively. in Unknown on line 0 If that iritating warning occurs then check the mistyped PHP variables assigned to session variable. I faced the same problem and half an hour after getting on my nerves I found the typing mistake and the infamous warning disappeared. As there aren't many articles when I googled, I thought this might be help someone.. Regards, Sachin Mahajan (essem76@xxxxxxxxx)