How to upgrade facebook messaging?

All of my friends have the new facebook messaging system, most of them have had it since the winter or early spring! I don't know why, but I still do not have it. I have hit that stupid link to get it countless times and it says that I will receive an invitation soon but I havent and I think the first time I hit that link was maybe four months ago. Is anyone else having this problem? and does anyone know how to ACTUALLY upgrade?