Need help with mysql/php "get"-function

[xprez]

Hi.

I have an ad-script, that creates ads in different categories, after you have registered as an user of the service. On the "index" - page it shows the number of ads in the categories in "()" after the category-name. But how do i get it to show the total number of ads in the categories AND subcategories in the same "()"?

Here`s the code:
[code]<?php include ("session.php");
$nav_section = "search";
include ("header.php");
[color=red]get_categories($_GET['cat_id']);

get_ads_in_cat($_GET['cat_id'], "full", "");[/color]

include ("footer.php"); ?>[/code]

The code in red, are the functions getting the number of ads in that category, but what do i change to get the total in subcategories as well?