, :
, …
!
http://inter-esy.ru/2012/04/22/%D1%81%D1%83%D0%B2%D0%B5%D0%BD%D0%B8%D1%80%D0%BD%D1%8B%D0%B5-%D1%82%D0%BE%D1%80%D1%88%D0%B5%D1%80%D1%8B-%D0%B8%D0%B7-%D0%B1%D1%83%D1%82%D1%8B%D0%BB%D0%BE%D1%87%D0%B5%D0%BA-%D0%BE%D1%82-%D0%B9%D0%BE/