ajax autorefresh?

[ERuiz]

I have this code, which I would like for it to refresh every 30 seconds, using ajax. Would someone know how to implement it on this code:

 

<?php
/**
* @version $Id: mod_whosonline.php 2726 2006-03-09 14:01:19Z stingrey $
* @package Joomla
* @copyright Copyright (C) 2005 Open Source Matters. All rights reserved.
* @license http://www.gnu.org/copyleft/gpl.html GNU/GPL, see LICENSE.php
* Joomla! is free software. This version may have been modified pursuant
* to the GNU General Public License, and as distributed it includes or
* is derivative of works licensed under the GNU General Public License or
* other free or open source software licenses.
* See COPYRIGHT.php for copyright notices and details.
*/

// no direct access
defined( '_VALID_MOS' ) or die( 'Restricted access' );

$showmode 	= $params->get( 'showmode', 0 );

$output 	= '';

// show online count
if ($showmode==0 || $showmode==2) {
$query = "SELECT guest, usertype"
. "\n FROM #__session"
;
$database->setQuery( $query );
$sessions = $database->loadObjectList();

// calculate number of guests and members
$user_array 	= 0;
$guest_array 	= 0;
foreach( $sessions as $session ) {		
	// if guest increase guest count by 1
	if ( $session->guest == 1 && !$session->usertype ) {
		$guest_array++;
	}
	// if member increase member count by 1
	if ( $session->guest == 0 ) {
		$user_array++;
	}
}

// check if any guest or member is on the site
if ($guest_array != 0 || $user_array != 0) {
	$output .= _WE_HAVE;

	// guest count handling
	if ($guest_array == 1) {
	// 1 guest only
		$output .= sprintf( _GUEST_COUNT, $guest_array );
	} else if ($guest_array > 1) {
	// more than 1 guest
		$output .= sprintf( _GUESTS_COUNT, $guest_array );
	}

	// if there are guests and members online
	if ($guest_array != 0 && $user_array != 0) {
		$output .= _AND;
	}

	// member count handling
	if ($user_array == 1) {
	// 1 member only
		$output .= sprintf( _MEMBER_COUNT, $user_array );
	} else if ($user_array > 1) {
	// more than 1 member
		$output .= sprintf( _MEMBERS_COUNT, $user_array );
	}

	$output .= _ONLINE;
}
}

// show online member names
if ($showmode > 0) {
$query = "SELECT DISTINCT a.username, a.userid"
."\n FROM #__session AS a"
."\n WHERE a.guest = 0"
;
$database->setQuery($query);
$rows = $database->loadObjectList();

if ( count( $rows ) ) {
	// output
	$output .= '<ul>';
	foreach($rows as $row) {
		$output .= '<li>';
		$output .= '<a href="index.php?option=com_wrapper&Itemid=30&bbact=pilotprofile.php?IDPilot='.$row->userid.'">';
		$output .= $row->username;
		$output .= '</a>';
		$output .= '</li>';
	}
	$output .= '</ul>';
}
}

echo $output;
?>

 

Thanks for any help,

 

ERuiz