JQuery Validator Plug-in help, please

JQuery Validator Plug-in help, please

Hi, I'm a newbie - please be gentle with me - we all have to start somewhere!!
I have a form that works fine, but I am having problems with getting the Validator Plug-in to work. I have scripted the form including the validator code.
However, when I try to use the same code in the live site, I get an error as follows:  Uncaught TypeError: Cannot call method 'setDefaults' of undefined , which is generated by the statements starting:
Copy code
  1. <script>
  2. $.validator.setDefaults({
  3. debug: true,
  4. success: "valid"...

My test page is at: