Sorry, that not possible for flash security reasons. A possibility could be to go fullscreen after a first user interaction, like clicking away the infoscreeen/usermanual.
Like Tuur says you can make a start page which forces the viewer to go fullscreen. Just use the same code on the entry image as on a fullscreen button.
Its a good way to embed panoramas on a clients site as you can insert it in any design on the page just using an iframe.
Just remember that fullscreen does not work on HTML5 so for iPad you need to make a special page you can link to.