Finding A Spoofed Website With A Javascript

Lots of people think that Javascript is an inferior language but Javascript is an extremly powerful language and those people who think the other way they either don't know how to use it or are not familiar with it's capabilities, With javascript you can do lots of cool things such as edit any page, make an image fly etc, but it is a waste of time to spend your time on making images fly with javascripts or editing a page.
Anyways coming to the main topic, did you know that javascript can be used to detect if a page is a spoofed website or phishing website or a legit one, well if you don't know just paste the following code in to the address bar and a pop up will appear telling you whether the website is original or not
Here is the Javascript code:

javascript:alert("The actual URL is:\t\t" + location.protocol + "//" + location.hostname + "/" + "\nThe address URL is:\t\t" + location.href + "\n" + "\nIf the server names do not match, this may be a spoof.");