function loadVideo(id,source) {
  // Load Video
  var video = document.getElementById(id);
  video.insertBefore(createSource(source, 'video/mp4; codecs="avc1.42E01E, mp4a.40.2"'), video.firstChild.nextSibling);
  
  video.style.display = "block";
}

function createSource(src, type) {
  var source = document.createElement('source');
  source.src = src;
  source.type = type;
  return source;
}