Cute, but it looks like it's trying too hard to be clever. Are you expecting websites to show a giant pop-up menu of 2-letter country codes to users? Or are y

Cute, but it looks like it's trying too hard to be clever. Are you expecting websites to show a giant pop-up menu of 2-letter country codes to users? Or are you expecting websites to hardcode one country, and reject phone numbers which don't match that pattern? And what about extensions? For dates, most browsers support form type="date" and the like. That's going to be better than whatever you use here. For credit cards, it's fine, because 16 decimal digits is a universal standard. For anything else, it's going to cause as many problems as it solves.