[bes]

<script src="http://code.jquery.com/jquery-latest.min.js"></script>
<script src="http://ajax.aspnetcdn.com/ajax/jquery.validate/1.11.1/jquery.validate.min.js"></script>
<form>
<input type="submit"/><br/>
</form>
<button>add</button>
<script>
jQuery(function ($) {
	var i = 0;
	$("button").on("click", function () {
		i++;
		$("form").append('inp' + i + ' <input name="inp' + i +'" required/><br/>');
		$("form").validate();
	});
});
</script>

<script src="http://code.jquery.com/jquery-latest.min.js"></script>
<script src="http://ajax.aspnetcdn.com/ajax/jquery.validate/1.11.1/jquery.validate.min.js"></script>
<form>
<input type="submit"/><br/>
</form>
<button>add</button>
<script>
jQuery(function ($) {
	var i = 0;
	var v = $("form").validate();
	$("button").on("click", function () {
		i++;
		$("form").append('inp' + i + ' <input name="inp' + i +'" required/><br/>');
		v.form();
	});
});
</script>