<?php
class forum extends domDocument {
    function __construct() {
        // domDocument constructor must be called to 
        // create the document.
        parent::__construct();
    }
                                
    // parameters: title, link, description, id
    function add_entry()
    {
        $elements = array('title','link','description');
        $args = func_get_args();

        // create a new node 
        $item = $this->createElement("item");

        // assign id to our new node
        $item->setAttribute("id", array_pop($args));

        // create elements for the new node
        foreach ($elements as $element) {
            // create element
            ${$element} = $this->createElement($element);

            // assign value to new element
            ${$element}->appendChild(
                $this->createTextNode(array_shift($args))
            );

            // append element to the node
            $item->appendChild(${$element});
        }

        // append new node to existing document
        $this->documentElement->appendChild($item);
    }
}
?>