Simple Category Tree

[some name not taken]

What are you trying to do?

Define session, then call on session with $content by the looks of things.

So I have now changed the code as follows

<?php
$_SESSION['category_tree']->build_deepest_level_children(), retrieve_cpath();
$content .= $_SESSION['category_tree']->build_category_string('ul', 'li', '', 0, 2);
?>

...but this, too, is not correct.