title: jQuery Validate: Not default value
body: <p>I have a category dropdown selection element in my form. The form is validated with jQuery as follows:</p>
  
  <pre><code>    $('#myForm').validate({
      rules: {
          text: {
                required: true
          },
          category: {
              required: true
          }
      },
      messages: {
          text: {
              required: "Text required"
          },
          category: {
              required: "Category required"
          }
      }
  </code></pre>
  
  <p>When loading the page, the default value of category is: '---' (without quotes). When I submit the form, the validation says eveything is ok, because '---' is not nothing. How can I get it to stop submitting when '---' is used as category? The other categories are something like this: Category1. One of the possibilities have to be choosen and I can't change the dropdown selection thing.</p>
  
  <p>Thanks!!</p>