Dunno which browser you're running, but if you have Chrome (or any number of clones) or Firefox, you can look up "Ad Block Plus" in the extension/add-on gallery. Install that (may or may not require a restart of the browser), then right click on the pop-up the next on that site and you should be able to see something like "block content" or similar from the context menu. Follow the instructions and that should take care of it.

ABP also gets rid of a bunch of those ad on fb, if you're into that.