JSFiddle - React, Tailwind, and code Playground

HTML

<form name="loginform" autocomplete="off" id="loginform" action="" method="post">
    <input type="text" required="required" />
    <br/>
    <input type="submit" value="submit" />
    <input type="submit" id="register" value="send" />
</form>

JavaScript

$("#register").on("click", function() {
    alert("I am executed before the HTML5 check!");
    return false;
});