title: jQuery form validation check returns 'undefined'
body: <p>I am having some trouble with a form I am trying to submit using jquery <code>$.post</code>, I am using <a href="http://www.position-absolute.com/articles/jquery-form-validator-because-form-validation-is-a-mess/" rel="nofollow noreferrer">this</a> validation plugin to validate the form, but when I try to check the form with <code>$("#form").validationEngine('validate')</code> I constantly get <code>undefined</code> and then the page reloads, here is the code:</p>
  
  <pre><code>$(document).ready(function() {          
  
          $("#form").validationEngine();
  
          $("#submit").live('click',function(){
              var valid = $("#form").validationEngine('validate');
              var vars = $("#form").serialize();
  
              if(valid == true){
  
                  //disable submit button
                  $("#submit").attr('disabled','disabled');
  
                  $.post('thank_you.php',vars,function(data){
                      alert(data);
                  });
  
              }else{
                  $("#form").validationEngine();
              }
          });
  });
  </code></pre>
  
  <p>the HTML:</p>
  
  <pre><code>&lt;form id="form"&gt;
      &lt;div&gt;
          &lt;label for='province'&gt;Select your current province &lt;/label&gt;
          &lt;select id='province' name='province' class='validate[required] text-input'&gt;
              &lt;option value=''&gt;Select one&lt;/option&gt;
              &lt;option&gt;province1&lt;/option&gt;
              &lt;option&gt;province2&lt;/option&gt;
          &lt;/select&gt;
      &lt;/div&gt;
      &lt;br /&gt;
      &lt;div&gt;
          &lt;label for="city"&gt;Select your current city&lt;/label&gt;&lt;br /&gt;
          &lt;select id="city" name="city" class="validate[required] text-input"&gt;
              &lt;option value=""&gt;Select one&lt;/option&gt;
              &lt;option&gt;city1&lt;/option&gt;
              &lt;option&gt;city2&lt;/option&gt;
          &lt;/select&gt;
      &lt;/div&gt;
      &lt;br /&gt;
      &lt;div&gt;
          &lt;label for="name_surname"&gt;Name &amp; Surname&lt;/label&gt;&lt;br /&gt;
          &lt;input type="text" id="name_surname" name="name_surname" class="validate[required] text-input" /&gt;
      &lt;/div&gt;
      &lt;br /&gt;
      &lt;div&gt;
          &lt;label for="email"&gt;Email Address&lt;/label&gt;&lt;br /&gt;
          &lt;input type="text" id="email" name="email" class="validate[required,custom[email]] text-input" /&gt;
      &lt;/div&gt;
      &lt;div&gt;
          &lt;input type="image" src="images/solar_38.gif" width="82" height="32" alt"submit" id="submit" /&gt;
      &lt;/div&gt;
  &lt;/form&gt;
  </code></pre>
  
  <p>I have had a look on the plugin's site, and have found nothing that could indicate why I am getting this, is there anything in my code that could be causing me to get <code>undefined</code> when I try to validate the form?</p>