Rated 5 out of 5 stars
Thanks for creating this extension! I've modified version 1.4.3 so it works with the latest versions of Firefox (working now in Firefox 29 as of this writing). You can download it here: http://bit.ly/1psQVvI
You will also need to install this extension so you can see the bottom status bar (where this extension is shown by default): https://addons.mozilla.org/es/firefox/addon/the-addon-bar/
In case you don't want to have a bottom bar at all times, once you're able to see the extension working in your browser you can move it from the status bar to other places using the "Customize" button located inside the menu which appears when clicking the [≡] button.
Remember to configure the extension to work with the 3.x beta by pressing Ctrl+Shift+A, clicking the "Options" button next to the "JSW:O Alert" extension, and finally selecting "3.x".
I hope you find this useful!