title: What is the difference of using addEventListener?
body: <p>What is the main difference between of using this...</p>
  
  <pre><code>document.addEventListener('mousedown', function() {
      // code
  }, false);
  </code></pre>
  
  <p>...and this?</p>
  
  <pre><code>document.onmousedown = function() {
      // code
  }
  </code></pre>
  
  <p><br/>
  Will there be any different result or any cause?</p>