test validator.settings undefined

jquery validator

HTML

<link rel="stylesheet" href="//code.jquery.com/ui/1.11.4/themes/smoothness/jquery-ui.css">
<script src="//code.jquery.com/jquery-1.1.4.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery-validate/1.15.1/jquery.validate.js"></script>
<script src="https://code.jquery.com/ui/1.11.4/jquery-ui.js"></script>
<h1 id="banner"><a href="http://jqueryvalidation.org/">jQuery Validation Plugin</a> Demo</h1>
<div id="main">
	<p>Default submitHandler is set to display an alert into of submitting the form</p>
	<form class="cmxform" id="commentForm" method="get" action="">
		<fieldset>
			<legend>Please provide your name, email address (won't be published) and a comment</legend>
			<p>
				<label for="cname">Name (required, at least 2 characters)</label>
				<input id="cname" name="name" minlength="2" type="text" required>
			</p>
			<p>
				<label for="cemail">E-Mail (required)</label>
				<input id="cemail" type="email" name="email" required>
			</p>
			<p>
				<label for="curl">URL (optional)</label>
				<input id="curl" type="url" name="url">
			</p>
			<p>
				<label for="ccomment">Your comment (required)</label>
				<textarea id="ccomment" name="comment" required></textarea>
			</p>
			<p>
				<input class="submit" type="submit" value="Submit">
			</p>
		</fieldset>
	</form>
  <input id="btnTest" type="button" value="Test">

JavaScript

$(document).ready(function() {

   var $Validator = $("#commentForm").validate();
 
   
	$( "#btnTest" ).button();
  $( "#btnTest" ).click(function () {
    var formID = $Validator.currentForm.id;
    alert('formID:'+formID);
    var form = $("#"+formID).get(0);
    $Validator.destroy();
	});
 });