title: JQuery custom validation error
body: <p>I am facing the following issue with the JQuery validator:
  I have a form where I am using the default validation rules provided and everything works fine.
  Howoever, as soon as I add a custom validation, the following error is thrown:</p>
  
  <ol>
  <li>in Chrome: Uncaught TypeError: Cannot call method 'addMethod' of undefined<br> </li>
  <li>in IE8: 'validator' is null or not an object<br></li>
  <li>FireFox: no error message, but the JQuery default validation logic breaks;</li>
  </ol>
  
  <p>The piece of code which is causing the error to occur is this (it sits inside the ready function):</p>
  
  <pre><code>$().validator.addMethod("defaultInvalid", 
     function(value, element) {   
      alert("validate");
     }
   );
  </code></pre>
  
  <p>As you see I have commented most of the code of the callback function in order to eliminate any other error.
  if I comment it, everything goes back to normal.
  However, I would like to use this customized rule on a text box taht must have the default value of "First name" and on submit it should not allow the user to send "First name" as value.</p>