Error WSE012 (Action Missing) when consuming WSE webservice

For a small project I 开发者_Python百科need to use (consume) an external (secure) webservice. This webservice uses SOAP1.2 protocol with WSE extention (username + password)

I use VB (VS2008) and added the Service Reference, customized the app.config to use wsHttpBinding rather than basicHttpBinding

One of the public Functions of the webservice is called

searchByName(String, String)As System.Xml.XmlElement

In code I first initialize the security;

wsTST.ClientCredentials.UserName.UserName = "mycompanyname"
wsTST.ClientCredentials.UserName.Password = "abc%2011!"

and then call the Function (the code fails here):

Debug.WriteLine(wsTST.searchByName("John", "Johnson"))

A first chance exception of type 'System.ServiceModel.FaultException' occurred in mscorlib.dll.

Error message: WSE012: The input was not a valid SOAP message because the following information is missing: action.

Can anyone tell me if consuming a WSE webservice is possible from VB.NET2008? And can anyone point me in the right direction?

I have searched for hours, but could not find any relevant information.

Regards, Frank