Fullscreen switch?!

Ok....search did not help.

I have a project in which I would like to switch between fullscreen and normal "windowed" mode.

Is that possible and if so, how?

It is a browser game... If applications could manipulate the browser window at will, that could turn out to be incredibly annoying, such as those ads that resize your browser.

You mean within the context of html page?

I think F11 + zooming is the best we're going to get.

Well, one can set the project either to fullscreen (crop or re-size) and you can have it "windowed" (Fullscreen off)

Though this can not be switched during runtime?

If so, can I program a crop for the fullscreen to reduce the field of vision?