allow an element to go fullscreen

The HTML5 Fullscreen API allows an element to be viewed filling the whole screen and hiding everything else. This can be used for example to play a video without distraction.

To view the element in fullscreen use:

requestFullscreen()

Users can leave fullscreen mode by pressing the ESC button and will be prompted to do so by an automatic alert.

There are inconsistencies in the implementation of this API between browsers and specific browsers may require identifiers.