There are 2 links tagged.
http://www.9lessons.info/2010/04/log-in-or-sign-up-with-jquery-and-php.html
Added: 24/04/10 Tags: php Login jquery
http://forums.devshed.com/php-development-5/preventing-multiple-logins-158339.html
Added: 25/06/06 Tags: php Login