[polopok]

lammer по этой теме куча исходников ...
https://www.google.ru/search?q=%D0%B8%D0%B3%D1%80%D0%B5+%D0%BC%D0%BE%D1% 80%D1%81%D0%BA%D0%BE%D0%B9+%D0%B1%D0%BE%D0%B9+%D0% B8%D1%81%D1%85%D0%BE%D0%B4%D0%BD%D0%B8%D0%BA%D0%B8 &ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:ru:official&client=firefo x