function fullscreenElement() {
  if (document.fullscreenElement) {
    return document.fullscreenElement;
  } else if (document.webkitFullscreenElement) {
    return document.webkitFullscreenElement;
  } else if (document.mozFullscreenElement) {
    return document.mozFullscreenElement;
  } else if (document.msFullscreenElement) {
    return document.msFullscreenElement;
  }

  return null;
}
/**
 * Returns the current fullscreened element or null
 *
 * @returns {Element|null}
 */
Returns the current fullscreened element or null
@returns {Element|null}
Returns the current fullscreened element or null @returns { Element|null }
function fullscreenElement() {
  if (document.fullscreenElement) {
    return document.fullscreenElement;
  } else if (document.webkitFullscreenElement) {
    return document.webkitFullscreenElement;
  } else if (document.mozFullscreenElement) {
    return document.mozFullscreenElement;
  } else if (document.msFullscreenElement) {
    return document.msFullscreenElement;
  }
  return null;
}
function fullscreenElement ( ) { if ( document . fullscreenElement ) { return document . fullscreenElement ; } else if ( document . webkitFullscreenElement ) { return document . webkitFullscreenElement ; } else if ( document . mozFullscreenElement ) { return document . mozFullscreenElement ; } else if ( document . msFullscreenElement ) { return document . msFullscreenElement ; } return null ; }
Returns the current fullscreened element or null
 @returns {Element|null}
Returns the current fullscreened element or null @returns { Element|null }