<html>
<head>
  <script>
    function playVideo()
    {
        document.getElementById("test-video").play();
    }
  </script>
</head>
<body>
    <p>
    <video id="test-video" src="test.mp4" controls></video>
    </p>
    <p>
    <button onclick="playVideo()">Play Video</button>
    </p>
</body>
</html>