ServerSide Validation through validation object

Vidly/Models/Customer.cs

@@ -10,11 +10,12 @@ namespace Vidly.Models
     {
         public int Id { get; set; }
 
-        [Required]
+        [Required(ErrorMessage ="Please enter customer's name.")]
         [StringLength(255)]
         public string Name { get; set; }
 
         [Display(Name = "Date of Birth")]
+        [Min18YearsIfAMember]
         public DateTime? BirthDate { get; set; }
 
         public bool IsSubscribedToNewsLetter { get; set; }