title: Eventlistener use this
body: <p>Hi I have the following code:</p>
  <pre><code>popupTriggerItems[i].addEventListener('click', function(){popup('left');}, false);
  
  var popup = function(which) {
      console.log(this);
      var id = this.getAttribute(&quot;id&quot;);
  }
  </code></pre>
  <p>But I get this output:</p>
  <blockquote>
  <p>Window #</p>
  <p>TypeError: this.getAttribute is not a function</p>
  </blockquote>
  <p>When using just popup() without an parameter the whole thing works. But I need this parameter. Why can't I access 'this' when using parameter?</p>
  <p>Thanks!</p>