Specifications

else

{

// if they weren’t logged in but came to this page somehow

echo “You were not logged in, and so have not been logged out.<br>”

;

}

The code’s very simple, but we do a little fancy footwork. We start a session, store the user’s

old username, deregister the valid user variable, and destroy the session. We then give the user

a message that will be different if she was logged out, could not be logged out, or was not

logged in to begin with.

This simple set of scripts will form the basis for a lot of the work we’ll do in later chapters.

Further Reading

Native sessions are new to PHP 4, but sessions have been provided by PHPLib for a while.

The best things to read for more information are the PHPLib homepage and the cookies speci-

fication. We’ve listed both these URLs earlier in the chapter, but we’ll reprint them here for

reference:

http://phplib.netuse.de/index.php3

http://home.netscape.com/newsref/std/cookie_spec.html

We’re almost finished with this section of the book.

Before we move on to the projects, we’ll briefly discuss some of the useful odds and ends of

PHP that we haven’t covered elsewhere.

Using Session Control in PHP

HAPTER 20

USING SESSION

ONTROL IN

PHP

445

LISTING 20.6 Continued

25 7842 CH20 3/6/01 3:42 PM Page 445