Embedded video, Javascript button to make it fullscreen?

Is i开发者_如何学编程t possible to have a button on a page that makes an embedded video go to the fullscreen mode when clicked using Javascript?

Seems there is no actual code to go fullscreen. You can enable the button and you can change the size. Here is the demo http://code.google.com/apis/youtube/youtube_player_demo.html (from here)