get $_session

Hello,
how can i set $_session[‘user_id’] and send it to event.php from
scheduler.load(“data/events.php”);
and then how can i get $_session[‘user_id’] in event.php

//------------------------------ event.php ----------------------------------//

<?php require_once('../../common/connector/scheduler_connector.php'); include ('../../common/config.php'); $scheduler = new schedulerConnector($res, $dbtype); if ($scheduler->is_select_mode())//code for loading data $scheduler->render_sql("SELECT * FROM `events` WHERE user_id=$_SESSION['user_id']","event_id","start_date,end_date,event_name,details"); else //code for other operations - i.e. update/insert/delete $scheduler->render_table("events","event_id","start_date,end_date,event_name,details"); ?>

make sure you’ve started the session with session_start(); http://php.net/manual/en/function.session-start.php