if(!isset($_GET["article_id"]) && !isset($_GET["category_id"])) {
		echo 'article id is not set, and no category id is set';
		foreach($tree as $parent_id=>$parent_array) {
		
			echo "\r<h2 class=\"categoryTitle\">" . $parent_array["title"] . '</h2>';
		
			$ADS->category_id = $parent_id;
			$category_articles = $ADS->get_articles_by_cat();
			
			$article_count = count($category_articles[$parent_id]);
			
			if (sizeof($category_articles) > 0) {
				echo "\r<ul class=\"category_articles\">";
				// Return each article for the given category	
				foreach($category_articles[$parent_id] as $article_id=>$article_array) {
					echo "\r<li><a href=\"" . $_SERVER["PHP_SELF"] . '?article_id=' . $article_id . '&category_id=' . $parent_id . '">' . $article_array["title"] . '</a></li>';
				}
				echo "\r</ul>";
			}	
		
		}
		
	}