chamilo-lms/main/inc/ajax/exercise.ajax.php

<?php
/* For licensing terms, see /license.txt */
/**
 * Responses to AJAX calls
 */
require_once '../global.inc.php';
if (api_is_anonymous()) {
    exit;
}

$action = $_REQUEST['a'];

switch ($action) {    
    case 'update_question_order':    
        $new_question_list     = $_POST['question_id_list'];
        $TBL_QUESTIONS = Database::get_course_table(TABLE_QUIZ_TEST_QUESTION);        
        $counter = 1;
        foreach ($new_question_list as $new_order_id) {            
            Database::update($TBL_QUESTIONS, array('question_order'=>$counter), array('question_id = ? '=>intval($new_order_id)));
            $counter++;
        }
        Display::display_confirmation_message(get_lang('Saved'));
        break;
    default:
        echo '';

}
exit;