SoapWS.myRequest req = new SoapWS.myRequest();
        // setup the request fields


        CustomBinding binding = new CustomBinding();
        binding.Namespace = "urn:<the name space>";
        binding.Name = "<name of binding>";
        TransportSecurityBindingElement securityElement = new TransportSecurityBindingElement();
        securityElement.IncludeTimestamp = true;


        X509Certificate cert = new X509Certificate(<from loaded bytes>);

        binding.Elements.Add(new TextMessageEncodingBindingElement(MessageVersion.Soap11, System.Text.Encoding.UTF8));
        binding.Elements.Add(securityElement);
        binding.Elements.Add(new HttpsTransportBindingElement());

        SoapWS.myRequestClient client = new SoapWS.myRequestClient(
            binding,
            addr);

        //client.ClientCredentials.UserName.UserName = "admin";
        //client.ClientCredentials.UserName.Password = "admin";

        using (new OperationContextScope(client.InnerChannel))
        {
            // Add a SOAP Header to an outgoing request
            MessageHeader aMessageHeader = MessageHeader.CreateHeader("Security", binding.Namespace, cert);
            OperationContext.Current.OutgoingMessageHeaders.Add(aMessageHeader);
        }

        client.myRequestCompleted += Client_completed;
        client.myRequestSessionAsync(req);