Custom URL Validation

Custom URL Validation

I have a form where visitors input a URL. I am using the validate plugin to check that the url is formed properly, but I want to take this (at least) one step further. I want to require that the URL *not* be a web site home page. I thought this could be accomplished by checking if the URL provided ends in .com, .net, .org etc. And I think I'd have to check whether it has a trailing slash or not - some submitted URLs will, some wont.

At first I thought this might be accomplished with regex. Then I looked at the regex in the validate.js file and knew instantly I'd never be able to write it. :) Some more searches indicated I might be able to use jquery to do this more simply. Can anyone here point me in the right direction?