V@no,
I solved this by myself.
But a problem is, its work on "a_example_page.php" but if the url is "a_example_page.php?id=abc" then content doesn't show.
I didn't find get_categories() in template.php
Why these lines used for in function.php?
global $site_template, $site_db, $site_sess, $config, $lang;
global $cat_cache, $cat_parent_cache, $new_image_cache, $subcat_ids;