Test if session is started

How do you test to see if sessions are on. This is not the way...

session_start();
if(isset($_SESSION)开发者_JAVA百科) {
    echo "sessions ON<br>";
}
else{
    echo "sessions OFF<br>";
}

session_destroy();
if(isset($_SESSION)) {
    echo "sessions ON<br>";
}
else{
    echo "sessions OFF<br>";
}

Try this:

if(session_id())

http://php.net/manual/en/function.session-id.php

session_start() itself will return boolean TRUE if the session was started successfully, boolean FALSE if not.