Apache Fatal Error Problem

[wilz04]

Hello friends,

I have problems with this:

MenuItem.class.php:

<?php
	class MenuItem {
		
		var $label;
		var $href;
		var $target;
		
		function MenuItem($label="", $href="", $target="") {
			$this->label = $label;
			$this->href = $href;
			$this->target = $target;
		}
		
		function isEmpty() {
			return $this->label == "" && $this->href == "" && $this->target == "";
		}
		
		function toString() {
			return "<td><a href='".$this->href."' target='".$this->target."'>".$this->label."</a></td>";
		}
		
	}
?>

MenuBar.class.php:

<?php
include_once("MenuItem.class.php");

class MenuBar {
	
	var $items;
	
	function MenuBar() {
		$this->items = array(new MenuItem());
	}
	
	function add($item) {
		if ($this->items[0]->isEmpty()) {
			$this->items[0] = $item;
		} else {
			$this->items[count($this->items)] = $item;
		}
	}
	
	function show() {
		$me = "<table><tr>";
		$j = count($this->items);
		for ($i=0; $i<$j; $i++) {
			$me .= $this->items[$i]->toString();
		}
		$me .= "</tr></table>";
	}
	
}
?>

menu.php:

<?php
	include_once("../scripts/MenuBar.class.php");
	
	$menu = new MenuBar();
	$menu->add("Google", "http://www.google.co.cr/", "_blank");
	$menu->show();
?>

The Apache return the follow error:

Fatal error: Call to a member function on a non-object in /home/iconco/public_html/invent/scripts/MenuBar.class.php on line 25

Can Helpme??