title: Pass key values pair as string to JQuery function
body: <p>If I try:</p>
  
  <pre><code>$("#test_form").validate({
      rules : {'code':'required'},
  </code></pre>
  
  <p>it works.
  If I try:</p>
  
  <pre><code>var my_rules="{code : 'required'}";
  $("#test_form").validate({
      rules : my_rules,
  </code></pre>
  
  <p>doesn't work.
  How I can pass values?
  Thanks.</p>