$(function(){
	$("#btn").click(function(){
		var docElm = document.documentElement;
		//W3C
		if(docElm.requestFullscreen) {
		  docElm.requestFullscreen();
		}
		//FireFox
		else if(docElm.mozRequestFullScreen) {
		  docElm.mozRequestFullScreen();
		}
		//Chrome等
		else if(docElm.webkitRequestFullScreen) {
		  docElm.webkitRequestFullScreen();
		}
		//IE11
		else if(elem.msRequestFullscreen) {
		  elem.msRequestFullscreen();
		}
	});

	$(document).keypress(function(e){   
		if(e.keyCode==27){
			alert("关闭页面");
			//W3C退出全屏
			/*if (document.exitFullscreen) {
				document.exitFullscreen();
			}
			//FireFox
			else if (document.mozCancelFullScreen) {
				document.mozCancelFullScreen();
			}
			//Chrome等
			else if (document.webkitCancelFullScreen) {
				document.webkitCancelFullScreen();
			}
			//IE11
			else if (document.msExitFullscreen) {
				document.msExitFullscreen();
			}*/
		}    
	});
});