Auto Refreshing A Xml File Load?

I have the following php script:

<?php
$doc = new DOMDocument();
$doc->load( 'events.xml' );
$events = $doc->getElementsByTagName( "event" );

[Code]....

If an event is taking place now the php script will show a div with information. This chapter is done and working, the trouble comes with the xml load part.

If the load of the xml document is done only once (when the page is first time loaded), I will need to refresh the php script so it looks for more times and info ..but the user will see the page reloading all the time.

I need the php script to look for the events' times in the xml file at all times, so I guess I have to do an auto refreshing of the

$doc->load( 'events.xml' );

how can I do that?