JSFiddle - React, Tailwind, and code Playground

HTML

<form action='/post' name='submitform' id="submitform" method='post' class='pure-form'>[...]
    <textarea columns="40" rows="4" name='entry[body]' id="statement"></textarea>
<input type='submit' id="submitbutton" name="btnSubmit" value="save" class="pure-button pure-button-primary">
</form>

JavaScript

document.querySelector('#submitform').addEventListener('submit', function(e) {
        e.preventDefault();
        alert('attempt');
 });