Hi!
Even when an operation does not take any parameters, you must have an <input> element inside its <operation> element, like this:
If you do not specify an <input> element, your operation will be a notification operation (see
http://www.w3.org/TR/wsdl#_notification). This message
exchange pattern is not allowed by the WS-I Basic Profile.
The input message for the above operation looks like this:
Hope this helps!