wsHttpBinding with username password

I am trying to set wsHttpBinding with username / password. The problem that I've ran into is how to set username / password?

I've set this:

binding.Security.Mode = SecurityMode.TransportWithMessageCredential;
      binding.Security.Message.ClientCredentialType = MessageCredentialType.UserName;

But where is the setting for username / password?

WSHttpBinding binding = new WSHttpBinding();
  binding.Security.Mode = SecurityMode.TransportWithMessageCredential;
  binding.Security.Message.ClientCredentialType = MessageCredentialType.UserName;


  Type contractType = typeof(ITest);
  Type serviceType = typeof(Test);
  Uri httpUri = new Uri("http://localhost:8083/Test2");
  ServiceHost myServiceHost = new ServiceHost(serviceType, httpUri);

  ServiceMetadataBehavior smb = new ServiceMetadataBehavior();
  smb.HttpGetEnabled = true;
  myServiceHost.Description.Behaviors.Add(smb);

  myServiceHost.Open();

Code:

namespace ConsoleApplication1
{
  [ServiceContract]
  interface ITest
  {
    [OperationContract]
    string Ping();
  }
}



namespace ConsoleApplication1
{
  class Test : ITest
  {
    public string Ping()
    {
      return "Pong - it works!";
    }
  }
}