title: Why is event.ctrlKey returning undef?
body: <p>I am calling a JavaScript function when an option is selected in a select element like so:</p>
  <pre><code>&lt;select id=&quot;select-thingy&quot; onchange=&quot;foo(event, this); false;&quot;&gt;
      &lt;option value=&quot;bar&quot;&gt;asdf&lt;/option&gt;
  ...
  &lt;/select&gt;
  </code></pre>
  <p>The function does something like this:</p>
  <pre><code>function foo(e, elem) {
      var thingummy = elem.options[elem.selectedIndex].value;
  
      alert(e.ctrlKey); // for testing only
  
      if (e.ctrlKey) {
          // do something
      } else {
          // do something else
      }
  }
  </code></pre>
  <p>According to the alert, <code>e.ctrlKey</code> is undefined - I thought this was supposed to return either true or false? What am I missing here?</p>