Session problem

[sjousse]

hi all!
I'm doing PHP since years but it's the first time I need to use sessions and I have some problems about it.
The 1st one is with this code:

<?php
    session_start();
    echo 'SID=' . SID;
?>

When I access this page, it prints the SID, when I refresh, SID disappear... I don't know if it's normal, php.ini-related, or else, what do you know about that?

Other problems will come later cause the 1st one may be the cause.
Thanks for your help!

[devinemke]

from the manual:

SID (string)
Constant containing either the session name and session ID in the form of "name=ID" or empty string if session ID was set in an appropriate session cookie.

use this:

session_start();
echo session_name() . '=' . session_id();