How to pass empty array to web services?

I’m using 3rd party web services to send data from our system. Some parameters to be sent needs to be null/nothing, but that seems to be impossible when dealing with arrays in Lotusscript.

When i try to invoke web service by sending uninitialized array as parameter Notes gives error:

Web Service MyService method mycalling_method error Attempt to use unknown datatype NoMethodError in web service MyService, method mycalling_method.

Has anyone ran into same error and situation?