function toggleFullScreen() { var doc = window.document; var docEl = doc.documentElement; var requestFullScreen = docEl.requestFullscreen || docEl.mozRequestFullScreen || docEl.webkitRequestFullScreen || docEl.msRequestFullscreen; var cancelFullScreen = doc.exitFullscreen || doc.mozCancelFullScreen || doc.webkitExitFullscreen || doc.msExitFullscreen; if(!doc.fullscreenElement && !doc.mozFullScreenElement && !doc.webkitFullscreenElement && !doc.msFullscreenElement) { requestFullScreen.call(docEl); } else { cancelFullScreen.call(doc); } }