Am using the enterprise library validation. 

I have classes like below 

```
 public class Customer
    {

        public int Id { get; set; }
        [NotNullValidator(MessageTemplate = "{1} is null")]
        public string FirstName { get; set; }
        [NotNullValidator(MessageTemplate = "{1} is null")]
        public string Surname { get; set; }

    }

  public class Order
    {

        public int Id { get; set; }
        [NotNullValidator(MessageTemplate = "{1} is null")]
        public Customer Customer { get; set; }

    }

```

When am using the order object and surname and first name are null validation should kick in ,but it does not.

What am i doing wrong? 

Note: Am using it with WCF