Code for exiting fullscreen mode using the HTML5 fullscreen API

exit-fullscreen.js

var btn02 = document.getElementById('btn-02');

// Exit full-screen mode when btn02
// is clicked
btn02.addEventListener('click', function(){
	
    exitFullscreen();	
	
}, false);

// Helper function for dealing
// with the various ways that
// different browsers handle
// exiting full-screen mode
function exitFullscreen() {
    
    if(document.exitFullscreen) {
        document.exitFullscreen();
    } else if(document.mozCancelFullScreen) {
        document.mozCancelFullScreen();
    } else if(document.webkitExitFullscreen) {
        document.webkitExitFullscreen();
    }
    
}