php man page for session_name

SESSION_NAME(3) 							 1							   SESSION_NAME(3)

session_name - Get and/or set the current session name

SYNOPSIS
       string session_name ([string  $name])

DESCRIPTION
       session_name(3) returns the name of the current session. If $name is given, session_name(3) will update the session name and return the old
       session name.

	The session name is reset to the default value stored in session.name at request startup time. Thus, you need to call session_name(3)  for
       every request (and before session_start(3) or session_register(3) are called).

PARAMETERS
	      o $name
		- The session name references the name of the session, which is used in cookies and URLs (e.g.	PHPSESSID). It should contain only
		alphanumeric characters; it should be short and descriptive (i.e. for users with enabled cookie warnings). If $name is	specified,
		the name of the current session is changed to its value.

	      Warning

		      The  session name can't consist of digits only, at least one letter must be present. Otherwise a new session id is generated
		     every time.

RETURN VALUES
	Returns the name of the current session. If $name is given and function updates the session name, name of the old session is returned.

EXAMPLES
       Example #1

	      session_name(3) example

	      <?php

	      /* set the session name to WebsiteID */

	      $previous_name = session_name("WebsiteID");

	      echo "The previous session name was $previous_name<br />";
	      ?>

SEE ALSO
	The session.name configuration directive .

PHP Documentation Group 													   SESSION_NAME(3)