Hello!

I'm trying to canceling an appointment via SOAP. I've successufuly created an appointment via SOAP. But 'm getting and error when trying to cancel.
INVALID_REQUEST: missing invId subpart: id should be specified as "item-inv". I searched everywere but i can't find any solution.

Code:
<soap:Envelope
	xmlns:soap="http://www.w3.org/2003/05/soap-envelope"
	xmlns:zmail="urn:zimbraMail">
	<soap:Header>
		<zimbra:context xmlns="urn:zimbraSoap">
			<zaccount:authToken>@USERTOKEN</zaccount:authToken>
		</zimbra:context>
	</soap:Header>
	<soap:Body>
		<zmail:CancelAppointmentRequest id="@ID">
		</zmail:CancelAppointmentRequest>
	</soap:Body>
</soap:Envelope>
Thanks in advanced!