xcode - Call a web service with MKNetworkoperation -

in our development team have implemented web service authenticate client. iphone application need send client's information web service , in order so, have written following function.

-(void)authenticateclient:(nsstring*)thecontractnumber            clientcode:(nsstring*)theclientcode             cellphone:(nsstring*)thecellphone               appleid:(nsstring*)theappleid  { nslog(@"begin send information web service",nil);  nsstring *uid = [uidevice currentdevice].uniqueidentifier;   nsdictionary *formparams = [nsdictionary dictionarywithobjectsandkeys:                             theclientcode, @"clientcode",                             thecontractnumber, @"contractcode",                             theappleid, @"appleid",                             @" ", @"androidid",                             @" ", @"windowsid",                             uid, @"appledeviceid",                             @" ", @"androiddeviceid",                             @" ", @"windowsdeviceid",                             thecellphone, @"telephonenumber"                             , nil];  mknetworkoperation *operation = [self.engine operationwithpath:@"/services/authentication.ashx"                                                         params: formparams                                                     httpmethod:@"post"]; [operation addcompletionhandler:  ^(mknetworkoperation *operation) {      nslog(@"%@", [operation responsestring]);  }                    errorhandler:^(mknetworkoperation *erroroperation, nserror *error) {                        nslog(@"%@", error);                    }]; [self.engine enqueueoperation:operation] ;   } 

the function works (or seems works no errors) in fact not anything. passes [operation addcompletionhandler: block not anything. have executed step step , again saw application reaches line , executes , directly goes [self.engine enqueueoperation:operation] line without going inside code block.

does can on this?

thank you.