public async Task RegisterDevice(NSData deviceToken)
		{
			var DeviceToken = deviceToken.Description;
			if (!string.IsNullOrWhiteSpace(DeviceToken)) {
				DeviceToken = DeviceToken.Trim('<').Trim('>');
			}

			LocalData ld = new LocalData ();
			DeviceRegistration dr = ld.GetDeviceRegistration ();
			bool needNewRegistration = false;
			if (dr != null) {
				dr = ld.GetDeviceRegistration ();
				//update registration
				DeviceRegistrationDTO drtoo = new DeviceRegistrationDTO () {
					Platform =  dr.Platform,
					Handle = dr.Handle,
					Tags = dr.Tags.Split('|'),
					RegistrationId = dr.RegistrationId
				};

				string result =	await client.InvokeApiAsync<DeviceRegistrationDTO,string> ("NotificationCustom/RegistrationUpdate/", drtoo);
				if (result == "gone") {
					needNewRegistration = true;
					ld.DeleteDeviceRegistration ();
				}
			}


			if (dr == null || needNewRegistration) {
				//get token
				string token = await client.InvokeApiAsync<string,string> ("NotificationCustom/RegistrationCreate/", " ");

				DeviceRegistrationDTO drto = new DeviceRegistrationDTO () {
					Platform = "apns",
					Handle = DeviceToken,
					Tags = new string[]{ "ios_users", "all_users", "userid_" + CurrentUser.Id, "areacode_" + CurrentUser.AreaCode },
					RegistrationId = token

				};

				//update registration
				string result = await client.InvokeApiAsync<DeviceRegistrationDTO, string> ("NotificationCustom/RegistrationUpdate/", drto);
				ld.InsertDeviceRegistration (dr);
			}
		}