JSFiddle - React, Tailwind, and code Playground

HTML

<html>
<head>
<style>
.hidden-div {
    display:none
}
</style>
</head>
<body>
<div class="reform">
    <form id="reform" action="action.php" method="post" enctype="multipart/form-data">
    <input type="hidden" name="type" value="" />
        <fieldset>
            content here...
        </fieldset>

            <div class="hidden-div" id="hidden-div">

        <fieldset>
            more content here that is hidden until the button below is clicked...
        </fieldset>
    </form>
            </div>
            <span style="display:block; padding-left:640px; margin-top:10px;"><button onclick="getElementById('hidden-div').style.display = 'block'; this.style.display = 'none'">Check Availability</button></span>
</div>
</body>
</html>