Custom shortcode not rendering

Question

Have used a code sample from internet to make a shortcode to return a certain page. However the shortcode does not seem to be rendering but shows the shortcode text as it. The function has been defined inside functions.php.

The code is as follows:

/* Code taken from: 
 * http://alex.leonard.ie/2010/09/09/wordpress-shortcode-to-insert-content-of-another-page/
 */

function pa_insertPage($atts, $content = null) {
     // Default output if no pageid given
     $output = NULL;
     // extract atts and assign to array
     extract(shortcode_atts(array(
     "page" => '' // default value could be placed here
     ), $atts));
     // if a page id is specified, then run query
     if (!empty($page)) {
     $pageContent = new WP_query();
     $pageContent->query(array('page_id' => $page));
     while ($pageContent->have_posts()) : $pageContent->the_post();
     // assign the content to $output
     $output = get_the_content();
     endwhile;
     }
     return $output;
}
add_shortcode('insert_page', 'pa_insertPage');

Answer 1

thank you for the help.. the shortcode seems to be rendering now (the issue was likely the wrong function.php file :) ) ..

It seems that the Theme had another functions.php file which was to be used.. (not sure if the theme made a duplicate copy or was mistakenly done by a developer .. :) ) ..

regards