Vertical Menu ( Smarty & Php )

I have a problem with one of my directories, i want a vertical menu and i have it using this code :

{php}
$result = mysql_query("SELECT * FROM `categories` ORDER BY `title` ASC");
echo mysql_error();
while($row = mysql_fetch_array($result)){
   ?>
   <li><a href="<?=$row['path']?>/"><?=$row['title']?></a></li>
   <?
   }
{/php} 

Code (markup):

The problem i have is the path, the path is incorrect when i browse one of the categories, example when i browse /category 1 and click "Category 2" i'm redirected to : category1/category2/ instead of /category2

Can anyone tell me how to modify or to make a change to this code to work ?

I received a sugestion to use a function like this : http://www.php.net/manual/en/function.strrpos.php#71882
but i don't know what and how to modify it.