title: jQuery.inArray() not working as expected
body: <p>What am I doing wrong here?  The idea is that I can separate the arrow key presses from anything else, but the every key press is firing the alert 'you pressed an arrow key'.  Any help would be great!</p>
  
  <p><a href="http://jsfiddle.net/UpHV5/" rel="noreferrer">jsFiddle</a> here or:</p>
  
  <pre><code>&lt;input id='foo'&gt;
  
  &lt;script&gt;
  
  $('#foo').keyup(function (e) {
      var key = e.keyCode;
      if ($.inArray(key, [37, 38, 39, 40])) {
          alert('you pressed an arrow key');
      } else {
          alert("you didn't press an arrow key");
      }
  });
  
  &lt;/script&gt;
  </code></pre>