On my web site I would like to have several sub-domains. Files that create context for a given sub-domain are stored in corresponding sub-directory.
Sometimes I nee
You're right that sessions cannot be shared in this way. However, you can use secure cookies to share user data across subdomains:
http://us3.php.net/manual/en/function.setcookie.php
Make sure the domain parameter when you set the cookie is something like
".mysite.org"
Then you'll be able to access the cookie from any subdomain of mysite.org