How use runAsync method with SOAP X3WebServices in VB.NET ?

SOLVED

Hi,

I am making a VB.NET application which uses SOAP web service with X3 V12.

It works very well in synchronous mode using run method.
But I would like to use this asynchronous function :

Public Overloads Sub runAsync(ByVal callContext As CAdxCallContext, ByVal publicName As String, ByVal inputXml As String, ByVal userState As Object)
   If (Me.runOperationCompleted Is Nothing) Then
     Me.runOperationCompleted = AddressOf Me.OnrunOperationCompleted
   End If
   Me.InvokeAsync("run", New Object() {callContext, publicName, inputXml}, Me.runOperationCompleted, userState)
End Sub

How to call it ?

How to indicate the callback method ?

thank you

Piotr