diff --git a/includes/mysql.php b/includes/mysql.php
index 81c016e..6ae070d 100755
--- a/includes/mysql.php
+++ b/includes/mysql.php
@@ -1,182 +1,187 @@
 <?php
 
 /**
  * MySQL layer and helper class
  *
  * Zed. The immensity of stars. The HyperShip. The people.
  *
  * (c) 2010, Dereckson, some rights reserved.
  * Released under BSD license.
  *
  * @package     Zed
  * @subpackage  Keruald
  * @author      Sébastien Santoro aka Dereckson <dereckson@espace-win.org>
  * @copyright   2010 Sébastien Santoro aka Dereckson
  * @license     http://www.opensource.org/licenses/bsd-license.php BSD
  * @version     0.1
  * @link        http://scherzo.dereckson.be/doc/zed
  * @link        http://zed.dereckson.be/
  * @filesource
  */
 
 if (!defined('SQL_LAYER')) {
     /**
      * Defines the SQL engine layer implented for our SQL abstraction class:
      * MySQL
      */
     define('SQL_LAYER', 'mysql');
 
     /**
      * SQL database class
      *
      * This is the MySQL implementation of our SQL abstraction layer
      */
     class sql_db {
         /*
          * @var int the connection identifier
          */
         private $id;
 
         /**
          * Initializes a new instance of the database abstraction class, for MySQL engine
          *
          * @param string $host the SQL server to connect [optionnal, by default localhost]
          * @param string $username the SQL username [optionnal, by default root]
          * @param string $password the SQL password [optionnal, by default blank]
          * @param string $database the database to select [optionnal]
          */
         function __construct($host = 'localhost', $username = 'root', $password = '' , $database = '') {
+            //Checks extension requirement
+            if (!function_exists("mysql_connect")) {
+                message_die(GENERAL_ERROR, "You've chosen to use a MySQL database engine, but the MySQL extension is missing.", "Setup issue");
+            }
+
             //Connects to the MySQL server
             $this->id = @mysql_connect($host, $username, $password) or $this->sql_die(); //or die ("Can't connect to SQL server.");
 
             //Selects database
             if ($database != '') {
                 mysql_select_db($database, $this->id);
             }
         }
 
 
         /**
          * Outputs a can't connect to the SQL server message and exits.
          * It's called on connect failure
          */
         function sql_die () {
             //You can custom here code when you can't connect to SQL server
             //e.g. in a demo or appliance context, include('start.html'); exit;
             //die ("Can't connect to SQL server.");
             include('start.html');
             exit;
         }
 
         /**
          * Sends a unique query to the database
          *
          * @param string $query the query to execute
          * @return resource if the query is successful, a resource identifier ; otherwise, false
          */
         function sql_query ($query) {
             return mysql_query($query, $this->id);
         }
 
         /**
          * Fetches a row of result into an associative array
          *
          * @param resource $result The result that is being evaluated, from sql_query
          * @return array an associative array with columns names as keys and row values as values
          */
         function sql_fetchrow ($result) {
             return mysql_fetch_array($result);
         }
 
         /**
          * Gets last SQL error information
          *
          * @return array an array with two keys, code and message, containing error information
          */
         function sql_error () {
             $error['code'] = mysql_errno($this->id);
             $error['message'] = mysql_error($this->id);
             return $error;
         }
 
 
         /**
          * Gets the number of rows affected or returned by a query
          *
          * @return int the number of rows affected (delete/insert/update) or the number of rows in query result
          */
         function sql_numrows ($result) {
             return mysql_num_rows($result);
         }
 
         /**
          * Gets the primary key value of the last query (works only in INSERT context)
          *
          * @return int  the primary key value
          */
         function sql_nextid () {
             return mysql_insert_id($this->id);
         }
 
         /**
          * Express query method, returns an immediate and unique result
          *
          * @param string $query the query to execute
          * @param string $error_message the error message
          * @param boolean $return_as_string return result as string, and not as an array
          * @return mixed the row or the scalar result
          */
         function sql_query_express ($query = '', $error_message = "Impossible d'exécuter cette requête.", $return_as_string = true) {
             if ($query === '' || $query === false || $query === null) {
                 //No query, no value
                 return '';
             } elseif (!$result = $this->sql_query($query)) {
                 message_die(SQL_ERROR, $error_message, '', __LINE__, __FILE__, $query);
             } else {
                 //Fetches row
                 $row = $this->sql_fetchrow($result);
 
                 //If $return_as_string is true, returns first query item (scalar mode) ; otherwise, returns row
                 return $return_as_string ? $row[0] : $row;
             }
         }
 
         /**
          * Escapes a SQL expression
          *
          * @param string $expression The expression to escape
          * @return string The escaped expression
          */
         function sql_escape ($expression) {
             return mysql_real_escape_string($expression);
         }
 
         /*
          * Sets the client character set (requires MySQL 5.0.7+).
          *
          * @param string $encoding the charset encoding to set
          */
         function set_charset ($encoding) {
             if (function_exists('mysql_set_charset')) {
                 //>=PHP 5.2.3
                 mysql_set_charset($encoding, $this->id);
             } else {
                 //Old PHP version
                 $this->sql_query("SET NAMES '$encoding'");
             }
         }
     }
 
     /**
      * The main sql_db instance
      *
      * @global sql_db $db
      */
     $db = new sql_db($Config['sql']['host'], $Config['sql']['username'], $Config['sql']['password'], $Config['sql']['database']);
     $db->set_charset('utf8');
 
     //By security, we unset the SQL parameters, so you can safely output Zed
     //config parts (there's still the problem of the secret key, but it's less
     //a security problem than database password)
     unset($Config['sql']);
 }