public function getCurrentLanguage() {
		if ( $this->currentLang === null ) {
			$lang = $this->defaultLanguage;
			if ( isset( $_REQUEST['uselang'] ) ) {
				$lang = $_REQUEST['uselang'];

			} elseif ( isset( $_SESSION['uselang'] ) ) {
				$lang = $_SESSION['uselang'];

			} else {
				$wants = self::parseAcceptLanguage();
				$bestMatches = array_intersect(
					$wants, $this->getAvailableLanguages()
				);
				if ( $bestMatches ) {
					$lang = current( $bestMatches );
				}
			}

			$this->setCurrentLanguage( $lang );
		}
		return $this->currentLang;
	}