JSFiddle - React, Tailwind, and code Playground

by Godfather

HTML

<form >
<input  placeholder="Username" required />
<input  type="password" placeholder="Password" required/>
<input type="submit" name="submit" value="Log In"/>

JavaScript

$(document).ready(function() {
    var elements = document.getElementsByTagName("INPUT");
    for (var i = 0; i < elements.length; i++) {
        elements[i].oninvalid = function(e) {
            e.target.setCustomValidity("");
            if (!e.target.validity.valid) {
                e.target.setCustomValidity("Username cannot be blank");
            }
        };
        elements[i].oninput = function(e) {
            e.target.setCustomValidity("");
        };
    }
})