Preloading Ajax Website

Hallo im using a wp in ajax language, so it load en entire page as whole website.
i was loooking for a good preloader.
there is one, ultimate preloader, but doesnt work properly ( bar moving in crazy way )

i was wondering if does exsist another Preloader for the whole website ( with percentage) or if i could use a free Jquery preloading sistem ( but i donnow where to put the codes ;(((((

Thanks a lot!!!