Autodetectar idioma som sites já com páginas traduzidas

Ola Pessoal, Eu tenho um site que já tem alguns idiomas, o [login to view URL] , mas ele não detectar automaticamente o idioma automaticamente e queria saber se alguém sabe como fazer isso, alguém pode me ajudar? Vou passar algumas páginas de código: **INCLUDE/CONFIG:** `<? $config = array(); // Begin Configuration $config['basedir'] = '---'; $config['baseurl'] = '---'; $default_language = "english"; //Valid options are english, french, spanish, portuguese, japanese, chinese_simplified or chinese_traditional // End Configuration session_start(); date_default_timezone_set('America/New_York'); $config['adminurl'] = $config['baseurl'].'/administrator'; $config['cssurl'] = $config['baseurl'].'/css'; $config['imagedir'] = $config['basedir'].'/img'; $config['imageurl'] = $config['baseurl'].'/img'; $config['pdir'] = $config['basedir'].'/pics'; $config['purl'] = $config['baseurl'].'/pics'; $config['mdir'] = $config['basedir'].'/mpics'; $config['murl'] = $config['baseurl'].'/mpics'; echo file_get_contents($config['baseurl']."/[login to view URL]"); require_once($config['basedir'].'/smarty/libs/[login to view URL]'); function strip_mq_gpc($arg) { $arg = str_replace('"',"'",$arg); $arg = stripslashes($arg); return $arg; } $conn = &ADONewConnection($DBTYPE); $conn->PConnect($DBHOST, $DBUSER, $DBPASSWORD, $DBNAME); @mysql_query("SET NAMES 'UTF8'"); $sql = "SELECT * from config"; $rsc = $conn->Execute($sql); if($rsc){while(!$rsc->EOF) { $field = $rsc->fields['setting']; $config[$field] = $rsc->fields['value']; STemplate::assign($field, strip_mq_gpc($config[$field])); @$rsc->MoveNext(); }} if ($_REQUEST['language'] != "") { if ($_REQUEST['language'] == "english") { $_SESSION['language'] = "english"; } elseif ($_REQUEST['language'] == "french") { $_SESSION['language'] = "french"; } elseif ($_REQUEST['language'] == "spanish") { $_SESSION['language'] = "spanish"; } elseif ($_REQUEST['language'] == "portuguese") { $_SESSION['language'] = "portuguese"; } elseif ($_REQUEST['language'] == "japanese") { $_SESSION['language'] = "japanese"; } elseif ($_REQUEST['language'] == "chinese_simplified") { $_SESSION['language'] = "chinese_simplified"; } elseif ($_REQUEST['language'] == "chinese_traditional") { $_SESSION['language'] = "chinese_traditional"; } } if ($_SESSION['language'] == "") { $_SESSION['language'] = $default_language; } if ($_SESSION['language'] == "english") { include("lang/[login to view URL]"); } elseif ($_SESSION['language'] == "french") { include("lang/[login to view URL]"); } elseif ($_SESSION['language'] == "spanish") { include("lang/[login to view URL]"); } elseif ($_SESSION['language'] == "portuguese") { include("lang/[login to view URL]"); } elseif ($_SESSION['language'] == "japanese") { include("lang/[login to view URL]"); } elseif ($_SESSION['language'] == "chinese_simplified") { include("lang/[login to view URL]"); } elseif ($_SESSION['language'] == "chinese_traditional") { include("lang/[login to view URL]"); } else { include("lang/".$default_language.".php"); } for ($i=0; $i<count($lang); $i++) { STemplate::assign('lang'.$i, $lang[$i]); } if($config['re_mobile'] == "1" && $config['m_url'] != "") ... ------------------------------------------------------------------- **e tem as paginas de idiomas no include/lang, veja um exemplo da English:** <? $lang = array(); $lang['0'] = "Login"; $lang['1'] = "Home"; ------------------------------------------------------------------ Tem também Portuguese, Spanish, Japanese