JSFiddle - React, Tailwind, and code Playground

HTML

<form id="form" onsubmit="return(login())">
<input name="username" placeholder="Username" required />
<input name="pass"  type="password" placeholder="Password" required/>
<br/>Remember me: <input type="checkbox" name="remember" value="true" /><br/>
<input type="submit" name="submit" value="Log In"/>

JavaScript

document.addEventListener("DOMContentLoaded", 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(r);
            }
        };
        elements[i].oninput = function(e) {
            e.target.setCustomValidity("");
        };
    }
})






































var r = "Йопаный говноюзер! Заполни поле!";