Вдумчиво читать тут:http://lurkmore.to/%D0%9F%D1%81%D0%B8%D1%85%D0%BE%D0%BB%D0%BE%D0%B3%D0%B8%D1%87%D0%B5%D1%81%D0%BA%D0%B8%D0%B5_%D1%82%D1%80%D0%B5%D0%BD%D0%B8%D0%BD%D0%B3%D0%B8