<?
session_start();

// set default phone number
$default_phone = '0844 999 8888';

// set timeout period in seconds
$default_session_expire = 1800; 

// check for expiry time presence
if (isset($_REQUEST['t']) && is_numeric($_REQUEST['t'])) {
	if ((int)$_REQUEST['t'] == $_REQUEST['t']) {
		$session_expire = $_REQUEST['t'];
		$_SESSION['expiry_time'] = $session_expire;
	}
} elseif (isset($_SESSION['expiry_time'])) {
	$session_expire = $_SESSION['expiry_time'];
} else {
	$session_expire = $default_session_expire;
}

// check to see if session timeout is set
if (isset($_SESSION['timeout'])) {	
	$session_life = time() - $_SESSION['timeout'];
	
	if ($session_life > $session_expire) { 
		session_destroy();
		session_unset(); 
	}
}

// check for phone number presence
if (isset($_REQUEST['adcall'])) {
	$phone = urldecode($_REQUEST['adcall']);
	$_SESSION['adcall'] = $phone;
} elseif (isset($_SESSION['adcall'])) {
	$phone = $_SESSION['adcall'];
} else {
	$phone = $default_phone;
}

$_SESSION['timeout'] = time();
?>