function exitFullscreen() {
  if(document.exitFullscreen) {
    document.exitFullscreen();
  } else if(document.mozCancelFullScreen) {
    document.mozCancelFullScreen();
  } else if(document.webkitExitFullscreen) {
    document.webkitExitFullscreen();
  } else if (document.msExitFullscreen) {
    document.msExitFullscreen();
  }
}
Gets the current URL params as an Object.
@method getURLParams
@return {Object} URL params
@example
<div class='norender'>
<code>
// Example: http://p5js.org?year=2014&month=May&day=15

function setup() {
  var params = getURLParams();
  text(params.day, 10, 20);
  text(params.month, 10, 40);
  text(params.year, 10, 60);
}
</code>
</div>
@alt
no display.