JSFiddle - React, Tailwind, and code Playground

HTML

<input type='button' id='test' value='test'/>

JavaScript

if(!(Event.prototype.stopEvent))
{
    Event.prototype.stopEvent = function(propagate)
    {
        "use strict";
        propagate = (propagate ? true : false);
        if (this.preventDefault)
        {
            this.preventDefault();
            if (propagate === false)
            {
                this.stopPropagation();
            }
        }
        else
        {
            this.returnValue = false;
            this.cancelBubble = !propagate;
        }
        return (this);
    };
}

function testEvent(e)
{
    e = e || window.event;
    if (e.stopEvent)
    {
        e.stopEvent();
        document.write('OK');
        return;
    }
    document.write('FFS');
}

window.onload = function()
{    
    document.getElementById('test').onclick = testEvent;
}