JSFiddle - React, Tailwind, and code Playground

HTML

<form id="frmName">
    <input type="text">
    <textarea>ololo trololo</textarea>
</form>
<input type="button" value="piu" onclick="toggle('frmName')">

JavaScript

function _e(id) {
    return document.getElementById(id);
}

function toggle(id) {
    for (i=0; i<_e(id).elements.length; i++)
        _e(id).elements[i].disabled = !_e(id).elements[i].disabled;
}