CODE EXAMPLE FOR HTML

full screen button in video tag html5

<script type="text/javascript">
function goFullscreen(id) {
  var element = document.getElementById(id);       
  if (element.mozRequestFullScreen) {
    element.mozRequestFullScreen();
  } else if (element.webkitRequestFullScreen) {
    element.webkitRequestFullScreen();
  }  
}
</script>


//Html code:

<video class="video_player" id="player" width="100%" controls="controls" autoplay="autoplay">
  <source src="INPUT VIDEO URL HERE"/>
  Your browser does not support the HTML5 video tag.  Use a better browser!
</video>
<button onclick="goFullscreen('player'); return false">
  View Fullscreen!
</button>