Zipcode validation that shows an error for particular states

[Th0r]

I'm trying to create a form that pops-up an error when people insert a specific zip code or range of zip codes.For example:If a potential lead fills out a form and enters a Washington state zip code I'd then want an error to pop-up to say we don't offer the product in that state. I've search Google and Stackoverflow but still haven't found a working example of code... I've seen ones that are similar but not exactly what my example says. the example I'm looking for could be in javascript or jquery