TalkPHP - Multilevel php menu

Hello.

I'm trying to make an multilevel menu. But the way i wan't it to work seems to be a bit complicated for me. I wan't the menu to work like this one(left menu): http://www.proconsult.dk/. The page must reload every time a menu has been clicked, because i wan't a new page to open (newest offers related to the clicked category).

So far i managed to get a non collapsable menu script:

PHP Code:


		
			
<?php 

// get all menuitems with 1 query 

$result = mysql_query("SELECT cat_id, cat_parent, cat_name FROM categories ORDER BY cat_id, cat_name ");



// prepare special array with parent-child relations 

$menuData = array( 

    'items' => array(), 

    'parents' => array() 

); 



while ($menuItem = mysql_fetch_assoc($result)) 

{ 

    $menuData['items'][$menuItem['cat_id']] = $menuItem; 

    $menuData['parents'][$menuItem['cat_parent']][] = $menuItem['cat_id']; 

} 



// menu builder function, parentId 0 is the root 

function buildMenu($parentId, $menuData) 

{ 

    $html = ''; 



    if (isset($menuData['parents'][$parentId])) 

    { 

        $html = '<ul>'; 

        foreach ($menuData['parents'][$parentId] as $itemId) 

        { 

            $html .= '<li>' . $menuData['items'][$itemId]['cat_name']; 



            // find childitems recursively 

            $html .= buildMenu($itemId, $menuData); 



            $html .= '</li>'; 

        } 

        $html .= '</ul>'; 

    } 



    return $html; 

} 



// output the menu 

echo buildMenu(0, $menuData);

?>

Just so you know. I don't want to use any Jquery, the menu must be pure php, if possible :-)
Thank you in advance.

Regards, Simon