title: jQuery inArray is always returning -1
body: <p>I cannot figure out why I keep getting -1 for lastProductIndex when clearly the lastProductID is in the array!</p>
  
  <pre><code>var lastProductID = 6758;
  var allProductIDs = [5410, 8362, 6638, 6758, 7795, 5775, 1004, 1008, 1013]
  var lastProductIndex = $.inArray(lastProductID, allProductIDs);
  </code></pre>