Delete alert

Hi,
I have a problem deleting alerts via the xml2 web service.
Each time I got an exception:TRYLATER: Failed to delete alert
Has somebody an idea what it could be the problem?

Thanks

Your user account “nagyendre” is not enabled for FlightXML access so you must be using a different user account?

The error message you indicated can be returned if the alert_id argument you specify is missing or is not a valid integer.