How to add a Custom EndPointBehavior to the web.config of the service?

I have followed this article and have created MyMessageInspector and MyEndPointBehavior clases as below:

public class MyMessageInspector : IDispatchMessageInspector
{
    public object AfterReceiveRequest(ref Message request, IClientChannel channel, InstanceContext instanceContext)
    { 
        Console.WriteLine("Incoming request: {0}", request);
        return null;
    }

    public void BeforeSendReply(ref Message reply, object correlationState)
    {
    }
}

public class MyEndPointBehavior : IEndpointBehavior
{
    #region IEndpointBehavior Members

    public void AddBindingParameters(ServiceEndpoint endpoint, BindingParameterCollection bindingParameters)
    {
    }

    public void ApplyClientBehavior(ServiceEndpoint endpoint, ClientRuntime clientRuntime)
    {
    }

    public void ApplyDispatchBehavior(ServiceEndpoint endpoint, EndpointDispatcher endpointDispatcher)
    {
        ChannelDispatcher channelDispatcher = endpointDispatcher.ChannelDispatcher;
        if (channelDispatcher != null)
        {
            foreach (EndpointDispatcher ed in channelDispatcher.Endpoints)
            {
                ed.DispatchRuntime.MessageInspectors.Add(new MyMessageInspector());
            }
        }
    }

    public void Validate(ServiceEndpoint endpoint)
    {
    }

    #endregion
}

How to add MyEndPointBehavior to the web.config?

I've added the below extensions:

<extensions>
  <behaviorExtensions>
    <add name="myMessageInspector" type="MessageInspectorProject.MyEndPointBehavior, MessageInspectorProject, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null"/>
  </behaviorExtensions>
</extensions>

But when I try to use it in below, it complains:

<serviceBehaviors>
    <behavior>