title: Can't generate routes through FOSJsRoutingBundle
body: <p>I'm using a AJAX call trough <code>$.ajax()</code> in one of my twig templates and because I need to call a URL so I'm using <a href="https://github.com/FriendsOfSymfony/FOSJsRoutingBundle/blob/master/Resources/doc/README.markdown" rel="nofollow">FOSJsRoutingBundle</a>. After read the docs, follow every steps and write this code in my template:</p>
  
  <pre><code>&lt;script&gt;
  $(function() {
      $("a.step").click(function() {
          var id = $(this).attr('id');
  
          $.ajax({
              type: 'GET',
              url: Routing.generate('category_subcategories', {parent_id: id}),
              dataType: "json",
              success: function(ev) {
                  // here I build the next
              }
          });
      });
  });
  &lt;/script&gt;
  </code></pre>
  
  <p>I got this error in Firebug console:</p>
  
  <pre><code>ReferenceError: Routing is not defined
  url: Routing.generate('category_subcategories', {parent_id: id}),
  </code></pre>
  
  <p>What could be wrong there?</p>
  
  <p><strong>UPDATE</strong></p>
  
  <p>The route at PHP controller is this one:</p>
  
  <pre><code>/**
   * Get subcategories based on $parent_id parameter
   *
   * @Route("/category/subcategories/{category_id}", name="category_subcategories", options={"expose"=true})
   * @Method("GET")
   */
  </code></pre>
  
  <p>Now it generate the route but cause this other error:</p>
  
  <blockquote>
    <p>"NetworkError: 404 Not Found -
    <a href="http://my.url.domain/app_dev.php/category/subcategories?parent_id=6" rel="nofollow">http://my.url.domain/app_dev.php/category/subcategories?parent_id=6</a>"</p>
  </blockquote>
  
  <p>Why? </p>