Starting session if authenticated

[Anon]

I need to start a session once a user has been authenticated. Simply an if, else statement - however when someone accesses a page within the site and HAS NOT been assigned to a session, it should not allow access. Can I check to see if there has been a session started and if not, require a login? I tried:

if (session_start() == NULL)

but that didn't work. How can I check to see if a visitor has been assigned a session?

Thanks!

[[deleted]]

You should allways start a session, and set a variable inside the session that determines if someone is loggedin or not.

[Anon]

I don't understand - how does that work or how do you do it?

Thanks

Seth

[[deleted]]

Just put 'session_start()' at the top of all you pages.
When a person first visits your pages, you initialize the session with
'loggedin=0'

That means the user has visited your site, but did not log on.
Then you present a login box, and when the user enters his username/password, you change the 'loggedin' from 0 to 1.

When the user logs out again, you set the 'loggedin' to zero.