Do you know any opensource JQuery dropdown menu for telephone prefix?

Well, you need a database which contains all the details of the phone-numbers, then you need to query the database through Ajax, return the results via Ajax too, and display it. After getting the results, you can create a div or p element of your own, populate them with the incoming data, and display it. if you don't want to do that, use jQuery UI Autocomplete.

I also needed this, so I built it.

Here is a live demo.

It currently has the following features:

• In the country dropdown you can navigate by typing, or using the up/down keys
• Selecting a country updates the dial code of the entered number
• Typing a different dial code automatically updates the displayed flag
• Option to specify "preferred countries" (which appear at the top of the list)

I built it out of the following open source projects:

• Flag images and CSS from https://github.com/lafeber/world-flags-sprite
• Country data from https://github.com/mledoze/countries
• Formatting and validation from the wonderful libphonenumber