Dim wcfClient As New SampleServiceClient(New InstanceContext(Me))
Try
  Using scope As New OperationContextScope(wcfClient.InnerChannel)
            Dim header As MessageHeader = MessageHeader.CreateHeader("Service-Bound-CustomHeader", _
                                "http://Microsoft.WCF.Documentation", "Custom Happy Value.")
    OperationContext.Current.OutgoingMessageHeaders.Add(header)

    ' Making calls.
    Console.WriteLine("Enter the greeting to send: ")
    Dim greeting As String = Console.ReadLine()

    'Console.ReadLine();
            header = MessageHeader.CreateHeader("Service-Bound-OneWayHeader", _
                                                "http://Microsoft.WCF.Documentation", "Different Happy Value.")
    OperationContext.Current.OutgoingMessageHeaders.Add(header)

    ' One-way
    wcfClient.Push(greeting)
    Me.wait.WaitOne()

    ' Done with service. 
    wcfClient.Close()
    Console.WriteLine("Done!")
    Console.ReadLine()
  End Using
Catch timeProblem As TimeoutException
  Console.WriteLine("The service operation timed out. " & timeProblem.Message)
  Console.ReadLine()
  wcfClient.Abort()
Catch commProblem As CommunicationException
  Console.WriteLine("There was a communication problem. " & commProblem.Message)
  Console.ReadLine()
  wcfClient.Abort()
End Try