static function Upper($text,$charset = null){
		static $TR_TABLES = array();

		$charset = self::_GetCharsetByName($charset);
		switch($charset){
			case "windows-1250":
			case "iso-8859-2":
				if(!isset($TR_TABLES[$charset])){
					require(dirname(__FILE__)."/tr_tables/lower_upper/$charset.php");
				}
				$text = strtr($text,$TR_TABLES[$charset]["mala"],$TR_TABLES[$charset]["velka"]);
				break;
			case "utf8":
				$text = mb_strtoupper($text,"utf8");
				break;
			case "ascii":
			default: 
				$text = strtoupper($text);
		}

		return $text;
	}