title: Toggle Fullscreen exit
body: <p>I have the following javascript that is triggered by a button in my HTML:</p>
  
  <pre><code>function toggleFullScreen(){
  
      if(v.requestFullScreen){
          v.requestFullScreen();
      }
      else if(v.webkitRequestFullScreen){
          v.webkitRequestFullScreen();
      }
      else if(v.mozRequestFullScreen){
          v.mozRequestFullScreen();
      }
  }
  </code></pre>
  
  <p>How can I extend this JS code to incorporate the ability to <strong>exit fullscreen</strong>? What are the best practices for this? </p>