<?php
    include dirname(__FILE__)."/dom_forum.inc.php";

    $dom = new forum();
    $dom->load(dirname(__FILE__)."/thedata.xml");
    $dom->add_entry("Yet Another Message", 
            "http://fud.prohost.org/forum/index.php/m/42",
            "You can never have enough messages.",
            "42");
    $output = $dom->saveXML();

    // output beautification for presentation
    echo nl2br(htmlspecialchars($output));
?>
Output
<?xml version="1.0"?>
<forum uri="http://fud.prohost.org/forum/index.php">

<item id="10084">
<title>Re: my dog has no nose</title>
<link>http://fud.prohost.org/forum/index.php/m/10084</link>
<description>Have you looked under it's tail?</description>
</item>

<item id="10149">
<title>Air Conditioner Broke</title>
<link>http://fud.prohost.org/forum/index.php/m/10149</link>
<description>I am melting..... HELP!!!</description>
</item>

<item id="42"><title>Yet Another Message</title><link>http://fud.prohost.org/forum/index.php/m/42</link><description>You can never have enough messages.</description></item></forum>