osCommerceITalia

Spero che possiate aiutarmi, non conosco nulla di php, sono un webdesign, ho l'incarico di sistemare graficamente un sito fatto in php osCommerce osCommerce Open Source appunto.

Ho la necessita di far costruire al codice php un menu fatto con una lista come questo di seguito:
<ul id='nav'>
<li class="menu"><a href="#">Categoria 1 </a>
<ul>
<li class='submenu'><a href="#">SubCategoria 1</a></li>
<li class='submenu'><a href="#">SubCategoria 2</a></li>
<li class='submenu'><a href="#">SubCategoria 3</a></li>
<li class='submenu'><a href="#">SubCategoria 4</a></li>
</ul>
</li>
<li class='menu'><a href="#">Categoria 2</a>
<ul>
<li class='submenu'><a href="#">SubCategoria 1</a></li>
<li class='submenu'><a href="#">SubCategoria 2</a></li>
<li class='submenu'><a href="#">SubCategoria 3</a></li>
<li class='submenu'><a href="#">SubCategoria 4</a></li>
</ul>
</li>
</ul>

Il codice che il webmaster mi ha realizzato è il seguente, ma non viene assolutamente quello che voglio io, come posso fare?:
<?php
/*
$Id: categories.php,v 1.25 2003/07/09 01:13:58 hpdl Exp $

osCommerce, Open Source E-Commerce Solutions
http://www.oscommerce.com

Copyright (c) 2003 osCommerce

Released under the GNU General Public License
*/

function tep_show_category($counter) {
global $tree, $categories_string, $cPath_array;
//$categories_string.="<ul id='nav'>";
for ($i=0; $i<$tree[$counter]['level']; $i++) {
$categories_string .= " ";
}
// BOF hi-lab

if ($tree[$counter]['parent'] == 0)
{
$categories_string.= '<li class="menu"><a href="';
}
else
{
$categories_string .= '<ul><li class="submenu"><a href="';
}

if ($tree[$counter]['parent'] == 0) {
$cPath_new = 'cPath=' . $counter;
} else {
$cPath_new = 'cPath=' . $tree[$counter]['path'];
}

$categories_string .= tep_href_link(FILENAME_DEFAULT, $cPath_new) . '">';

if (isset($cPath_array) && in_array($counter, $cPath_array)) {
$categories_string .= '<b>';
}

// display category name
$categories_string .= $tree[$counter]['name'];

if (isset($cPath_array) && in_array($counter, $cPath_array)) {
$categories_string .= '</b>';
}

if (tep_has_category_subcategories($counter)) {
$categories_string .= '...'; //$categories_string .= '>>';
}

//$categories_string .= '</a></li></ul>';
if ($tree[$counter]['parent'] == 0)
$categories_string .= '</a>';
else
$categories_string .= '</a></li></ul>';


if (SHOW_COUNTS == 'true') {
$products_in_category = tep_count_products_in_category($counter);
if ($products_in_category > 0) {
// $categories_string .= ' (' . $products_in_category . ')';
}
}

$categories_string .= '';

if ($tree[$counter]['next_id'] != false) {
tep_show_category($tree[$counter]['next_id']);
}
}
?>
<!-- categories //-->
<tr>
<td>
<?php
$info_box_contents = array();

// $info_box_contents[] = array('text' => BOX_HEADING_CATEGORIES);
$info_box_contents[] = array('text' =>'<img src="images/titolo-categorie.gif" align="absmiddle"> <span class="titolo-medio-piccolo">Categorie</span>');
// EOF HI-lab

new infoBoxHeading($info_box_contents, false, false);

$categories_string = '';
$tree = array();

$categories_query = tep_db_query("select c.categories_id, cd.categories_name, c.parent_id from " . TABLE_CATEGORIES . " c, " . TABLE_CATEGORIES_DESCRIPTION . " cd where c.parent_id = '0' and c.categories_id = cd.categories_id and cd.language_id='" . (int)$languages_id ."' order by sort_order, cd.categories_name");
while ($categories = tep_db_fetch_array($categories_query)) {
$tree[$categories['categories_id']] = array('name' => $categories['categories_name'],
'parent' => $categories['parent_id'],
'level' => 0,
'path' => $categories['categories_id'],
'next_id' => false);

if (isset($parent_id)) {
$tree[$parent_id]['next_id'] = $categories['categories_id'];
}

$parent_id = $categories['categories_id'];

if (!isset($first_element)) {
$first_element = $categories['categories_id'];
}
}

//------------------------
if (tep_not_null($cPath)) {
$new_path = '';
reset($cPath_array);
while (list($key, $value) = each($cPath_array)) {
unset($parent_id);
unset($first_id);
$categories_query = tep_db_query("select c.categories_id, cd.categories_name, c.parent_id from " . TABLE_CATEGORIES . " c, " . TABLE_CATEGORIES_DESCRIPTION . " cd where c.parent_id = '" . (int)$value . "' and c.categories_id = cd.categories_id and cd.language_id='" . (int)$languages_id ."' order by sort_order, cd.categories_name");
if (tep_db_num_rows($categories_query)) {
$new_path .= $value;
while ($row = tep_db_fetch_array($categories_query)) {
$tree[$row['categories_id']] = array('name' => $row['categories_name'],
'parent' => $row['parent_id'],
'level' => $key+1,
'path' => $new_path . '_' . $row['categories_id'],
'next_id' => false);

if (isset($parent_id)) {
$tree[$parent_id]['next_id'] = $row['categories_id'];
}

$parent_id = $row['categories_id'];

if (!isset($first_id)) {
$first_id = $row['categories_id'];
}

$last_id = $row['categories_id'];
}
$tree[$last_id]['next_id'] = $tree[$value]['next_id'];
$tree[$value]['next_id'] = $first_id;
$new_path .= '_';
} else {
break;
}
}
}
tep_show_category($first_element);

$info_box_contents = array();
$info_box_contents[] = array('text' => "<ul id='nav'>".$categories_string."</ul>");

?>
<tr>
<td><ul>
<?
new infoBox($info_box_contents);
?>
</ul></td>

</td>
</tr>
<!-- categories_eof //-->