php - Fatal error: Call to undefined function get_all_subjects() in -

i trying teach myself php & mysql. please note new this. below error message getting , code.

i hope makes sense!!!

fatal error: call undefined function get_all_subjects() in /users/darren/sites/widget_corp/content.php on line 9

content.php code

<?php require_once("includes/connection.php"); ?> <?php require_once("includes/functions.php"); ?> <?php include("includes/header.php"); ?> <table id="structure"> <tr> <td id="navigation"> <ul class="subjects"> <?php $subject_set = get_all_subjects(); **// problem line** while ($subject = mysql_fetch_array($subject_set)) { echo "<li><a href=\"content.php?subj=" . urlencode($subject["id"]) .      "\">{$subject["menu_name"]}</a></li>"; $page_set = get_pages_for_subject($subject["id"]); echo "<ul class=\"pages\">"; while ($page = mysql_fetch_array($page_set)) {     echo "<li><a href=\"content.php?page=" . urlencode($page["id"]) .         "\">{$page["menu_name"]}</a></li>"; } echo "</ul>"; }  ?> </ul> </td> <td id="page"> <h2>content area</h2>  </td> </tr> </table> <?php require("includes/footer.php"); ?> 

this functions code resides in folder called "includes"

</php // store basic functions  function confirm_query($result_set) { if (!$result_set) { die("database selection failed: " . mysql_error()); }        }  function get_all_subjects() { global $connection; $query = "select *  subjects  order position asc"; $subject_set = mysql_query($query, $connection); confirm_query($subject_set); return $subject_set; }  function get_pages_for_subject($subject_id) { global $connection; $query = "select *  pages  subject_id = {$subject_id"}  order position asc";              $page_set = mysql_query($query, $connection); confirm_query($page_set); return $page_set;    } ?> 

your functions code has mal-formed opening <?php tag - you've got </php. without opening tag, php process file plaintext , never treat php code. means function never got defined.

remember there not such things "php script". there text files happen contain php code blocks. opening <?php tag required @ point in file, otherwise 'code' text.