title: AddEventListener: onmousedown
body: <p>I am creating a Chrome Extension which checks to see if there is "onmousedown" attribute and if so I will execute some code.</p>
  
  <p>I have tried this however it isn't working.</p>
  
  <pre><code>document.addEventListener("onmousedown", function() {
  
  });
  </code></pre>