Form of fbrequest

I'm using fbconnect in my app to connect to Facebook. Whenever i code a feature, I must google to find the form like below:

//////
NSString *event = @"{\"name\":\"A party\",\"start开发者_开发技巧_time\":\"1215929160\",\"end_time\":\"1215929160\",\"location\":\"Somewhere\"}";
NSDictionary *params = [NSDictionary dictionaryWithObject:event forKey:@"event_info"];
[[FBRequest requestWithDelegate:self] call:@"facebook.events.create" params:params];
/////

I wonder how can I know the format of string "event", or key @"event_info", or @"facebook.events.create". I try to find document of fbconnect that talk about format above but ... Anybody can help me about this. Thanks

It's here: events.create