How to make this pop-up window, with form?

Just curious how to make this pop-up window.

Is this a mix of CSS plus javascript?
Or can you show me samples of codes of how this is made?

Noticed also it has a form in it.
Any one would like to explain how this is done?

Thanks in advanced.

It’s done with a lightbox it looks like. Fancybox is your best bet. Put the form on an outside page and call it with class iframe in your link. This explains it all

I’ll try it later…

Thank you EricWatson.