code: function enterFullscreen(element) {
          var userAgent = navigator.userAgent.toLowerCase();
          if (element.requestFullscreen) {
              element.requestFullscreen();
          }
          else if (element.msRequestFullscreen) {
              element.msRequestFullscreen();
          }
          else if (element.mozRequestFullScreen) {
              element.parentElement.mozRequestFullScreen();
          }
          else if (userAgent.indexOf('edge') != -1) {
              element.parentElement.webkitRequestFullscreen();
          }
          else if (element.webkitRequestFullscreen) {
              element.webkitRequestFullscreen();
          }
      }
docs: enter fullscreen mode.
  @param {Element} element