[C++] whare can i find StateObject

Hello

I am working on an XMLSocket server
I am also a C++ beginner
I have got quite far but now the MSDN help has left me to dry

I am trying to get beginreceive to work but i am having problems with
StateObject* so2 = new StateObject();
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfsystemnetsocketssocketclassbeginreceivetopic. asp
get errors
error C2065: 'StateObject' : undeclared identifier
error C2065: 'so2' : undeclared identifier
error C2061: syntax error : identifier 'StateObject'
so i thougth it could be a my namespace
but i can't find any info on StateObject

plz help Johnny