JSFiddle - React, Tailwind, and code Playground

JavaScript

function send (method, url, data)
{      
    var xhr = new XMLHttpRequest();

    xhr.ontimeout = function()
    {
        alert('timeout');
    }

    xhr.onload = function() 
    {
        if (xhr.readyState === 4) 
        { 
            if (xhr.status === 200) 
            {
                alert('success');
            } 
            else 
            {
                alert('failed');
            }
        }
        else
        {
            alert('failed');
        }
    };

    try
    {
        xhr.timeout = 10000;
        xhr.open(method, url, true);
        xhr.send(data);
    }
    catch(er)
    {
        alert('failed');
    }
}

send('POST', '/echo/jsonp/', null);