Encoding a message

PipeParser parser = new PipeParser(); 
NHapi.Model.V231.Message.QRYR02 qry = new NHapi.Model.V231.Message.QRYR02(); 
qry.MSH.MessageType.MessageType.Value ="QRY";
qry.MSH.MessageType.TriggerEvent.Value = "R02";
qry.MSH.MessageType.MessageStructure.Value = "QRY_R02";
qry.MSH.FieldSeparator.Value = "|";
qry.MSH.SendingApplication.NamespaceID.Value="CohieCentral";
qry.MSH.SendingFacility.NamespaceID.Value = "COHIE";
qry.MSH.ReceivingApplication.NamespaceID.Value="Clinical Data Provider"; qry.MSH.ReceivingFacility.NamespaceID.Value=facility;
qry.MSH.EncodingCharacters.Value = @"^~\&";
qry.MSH.VersionID.VersionID.Value = "2.3.1";
qry.MSH.DateTimeOfMessage.TimeOfAnEvent.SetLongDate(DateTime.Now);
qry.MSH.MessageControlID.Value = messageControlId;
qry.MSH.ProcessingID.ProcessingID.Value="P"; 
XCN st = qry.QRD.getWhoSubjectFilter(0); st.AssigningAuthority.UniversalID.Value = facility; 
st.IDNumber.Value = mrn;
qry.QRD.QueryDateTime.TimeOfAnEvent.SetLongDate(DateTime.Now); 
qry.QRD.QueryFormatCode.Value = "R";
qry.QRD.QueryPriority.Value = "I";
CE what = qry.QRD.getWhatSubjectFilter(0);
what.Identifier.Value = "RES"; 
return parser.encode(qry);