How to alert users when connection is gone using Offline.js

Question

I'm trying to alert users when they are offline, and show a simple message. I'm using Offline.js as a library (Offline.js website).

I want to write JS and not use Eager to install it automatically.

Here is what I wrote, but it doesn't seem to be working. Can someone help me with more details?

I couldn't find a sample with code on the library website.

Offline.options = {checkOnLoad: true, checks: {image: {url: 'http://www.vitaminedz.com/photos/49/02-49565-front-de-mer-a-oran.jpg'}, active: 'image'}}

Offline.check();
Offline.on('up', alert('up'));
Offline.on('down',alert('down'));

JSFiddle Code + DEMO

Answer 1

Your handlers are not set properly. It should be like this:

alert(Offline.check());
Offline.on('up', function() {
    alert('up');
});
Offline.on('down', function() {
    alert('down')
});