There is a function called session_set_cookie_params? Does this function modify the default session behavior set in php.ini?

I tried. Seems it does not work at all. In forum PHPBB seems they are doing their SESSION via cookie.

Why i am concerned with this is that i want to control the session time instead of default value.

Another thing about session it that even on PHP v4.1.0 or higher. The way recommended in PHP Manual does not always work.
+++++++++++++++++++++++++
<?php
session_start();
// Use $HTTP_SESSION_VARS with PHP 4.0.6 or less
if (!isset($_SESSION['count'])) {
    $_SESSION['count'] = 0;
} else {
    $_SESSION['count']++;
}
?>
+++++++++++++++++++++++++

seems sometimes have to use session_register() to register a session.