Auto Logout in php

Copy and paste this code on youre page
you can change time as your need i take 60 sec .
< ? php
session_start();

// set timeout period in seconds
$inactive = 60;

// check to see if $_SESSION['timeout'] is set
if(isset($_SESSION['timeout']) ) {
$session_life = time() - $_SESSION['timeout'];
if($session_life > $inactive)
{
// go to login page when idle
session_destroy(); header("Location: logout.php");
}
}?>