JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://ajax.aspnetcdn.com/ajax/jquery.validate/1.9/jquery.validate.js"></script>
<form action="" method="post" class="validateForm">
    <label for="firstname">firstname</label>
    <span class="validateMe">
        <input type="text" name="firstname" id="firstname" class="required">
    </span>
    <br/>
    <label for="firstname">secondname</label>
    <input type="text" name="secondname" id="secondname">

    <button data-url="/draaiboek-frontend/poc/hotel/step2" data-event="next" class="event button green" type="submit">next</button>
</form>

<div id="ajaxContainer"></div>

JavaScript

(function($) {
    var validationOptions = {
        ignore: '',
        wrapper: "div",
        errorElement: "div",
        errorClass: "message",
        errorPlacement: function(error, element) {
            error.insertAfter(element.parents("span"));
            error.addClass('error');
        },
        rules: {},
        messages: {},
    };

    var data = '<form action="" method="post" class="validateForm">' + '<label for="firstname">firstname</label>' + '<span class="validateMe">' + '<input type="text" name="firstname" id="firstname" class="required">' + '</span>' + '<br/>' + '<label for="firstname">secondname</label>' + '<input type="text" name="secondname" id="secondname">' + '<button data-url="/draaiboek-frontend/poc/hotel/step2" data-event="next" class="event button green" type="submit">next</button>' + '</form>';

    $(document).ready(function() {
        var $form = $('.validateForm'),
            $required = $('input.required', $form);

        var ajaxTaskContainer = $("#ajaxTaskContainer");

        function setValidationRules() {
            $(this).rules("add", {
                required: true,
                messages: {
                    required: "Dit veld is verplicht."
                }
            });
        }

        function ajaxSuccess(data) {
            console.log(data);
            $('#ajaxContainer').html(data);
        }


        $(document).on("click", ".event", function(e) {
            e.preventDefault();
            var formData = $('#ajaxTaskContainer form');
            var formEvent = $(this).attr("data-event");
            var dataUrl = $(this).attr("data-url");

            $(ajaxTaskContainer).empty().html('<span class="ajaxLoader">');
            $.ajax({
                type: "POST",
                url: '/echo/html/',
                data: {
                    html: data,
                    delay: 1
                },
                cache: false,
                success: ajaxSuccess
            });
      ...