My website where I'm using SJ Video Box: 4lo-lukow.pl/galeria/filmy

I'm from Poland and I've got very big problem with your extension...
I can't choose any of videos from "Layout". Just visit my website and try to switch video - mission impossible!

Bugged javascript or something else? I'm JOOMLA begginer, so please - help me "step by step".

I want your extension (it looks great) and if you help me - i would reccomend it