Problem with codepage in popup window after adding to cart

Hi.
I meet a problem while using russian names for items. There is a problem on popup window after adding to cart http://textileinks.ru/dupont/chistyashc ... tra-detail
Where can i change the codepage for it?

Hi

Please take a look at this post: https://www.gavick.com/forums/140/trans ... em#p119458