<!DOCTYPE html>
<html>
<body>
<video width="320" height="240" controls>
<source id="mySource" src="movie.mp4" type="video/mp4" media="screen and (min-width:320px)">
<source src="movie.ogg" type="video/ogg" media="screen and (min-width:320px)">
Your browser does not support the video tag.
</video>
<p>Click the button to return the value of the media attribute of the media resource.</p>
<p id="demo"></p>
<button onclick="myFunction()">Try it</button>
<script>
function myFunction() {
var x = document.getElementById("mySource").media;
document.getElementById("demo").innerHTML = x;
}
</script>
</body>
</html>