Poke or SuperPoke! feature, Help!

[christian8a]

Ive seen this in facebook and other dating sites, well , looks like a simple thing to do but I dont know exactly what will it take to make that possible

What I need is basically when they click on Poke! it will send a PM to them saying
"user name" poked you or You have been poked by "user name"

also a nice option would be , return poke to "user name"?

Could somebody help me on this?
willing to pay if needed

I posted another thread on paid services but ill try to make it, so help me