Facebook API: Check In to an Event?

I can't find any information about event checkins. Facebook do this in their application and I want to allow users to do the same within my application:

• How do I checkin a user to a Facebook event?

• How do I retrieve all of the us开发者_如何学编程ers checked into an event?

I have tried replacing the 'place id' with an 'event id', which didn't work. I don't know what to try or what will work. Can anyone help?

---

   eid = 327125807317374;
   location = "bla bla";
   name = cars;
   "start_time" = 1324166400;
   venue =         {
       city = "";
       country = "";
       id = 207275525951980;
       latitude = "-6.17151";
       longitude = "106.82774";
       state = "";
       street = "";
   }; 

the event has a venue object. inside this is an id which (sometimes) corresponds to a place. Use this place id to check in.

---

You can't check in to an event or retrieve checked in users from an event.

---

Not exaclty, that will checkin on the Place, not the Event.