检测浏览器是否支持HTML5视频

function checkVideo()
{
	if(!!document.createElement('video').canPlayType){
		var vidTest=document.createElement("video");
		oggTest=vidTest.canPlayType('video/ogg; codecs="theora, vorbis"');
		if (!oggTest){
			h264Test=vidTest.canPlayType('video/mp4; codecs="avc1.42E01E, mp4a.40.2"');
			if (!h264Test){
				document.getElementById("checkVideoResult").innerHTML="Sorry. No video support."
			}else{
				if (h264Test=="probably"){
					document.getElementById("checkVideoResult").innerHTML="Yes! Full support!";
				}
				else{
					document.getElementById("checkVideoResult").innerHTML="Well. Some support.";
				}
			}
		}
		else{
			if (oggTest=="probably"){
				document.getElementById("checkVideoResult").innerHTML="Yes! Full support!";
			}
			else{
				document.getElementById("checkVideoResult").innerHTML="Well. Some support.";
			}
		}
	}
	else{
		document.getElementById("checkVideoResult").innerHTML="Sorry. No video support."
	}
}