Validation in .NET Framework 4

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.ComponentModel.DataAnnotations;

namespace ValidationSample
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void BtnValidate_Click(object sender, EventArgs e)
        {
            Customer entity = new Customer { Title = TxtTitle.Text, FirstName = TxtFName.Text, LastName = TxtLName.Text };
            GenericValidator<ICustomer> target = new GenericValidator<ICustomer>();
            if (target.Validate(entity).Count == 0)
                MessageBox.Show("Validation Successfull - No Data Errors");
            else
            {
                IList<ValidationResult> Results = target.Validate(entity);
                foreach (ValidationResult Result in Results)
                    MessageBox.Show(Result.ErrorMessage);
            }
        }
    }

    public interface ICustomer
    {
        String FirstName { get; set; }
        string LastName { get; set; }
        string Title { get; set; }
    }

    public sealed class Customer : ICustomer
    {
        /// <summary>
        /// Gets or sets the first name.
        /// </summary>
        /// <value>The first name.</value>
        [Required(ErrorMessage = "The FirstName is a mandatory Field")]
        [StringLength(10, ErrorMessage =
        "The FirstName should not be greater than 10 characters.")]
        public string FirstName { get; set; }

        /// <summary>
        /// Gets or sets the last name.
        /// </summary>
        /// <value>The last name.</value>
        [Required(ErrorMessage = "The LastName is a mandatory Field")]
        [StringLength(10, ErrorMessage =
        "The LastName should not be greater than 10 characters.")]
        public string LastName { get; set; }

        /// <summary>
        /// Gets or sets the title.
        /// </summary>
        /// <value>The title.</value>
        [Required(ErrorMessage = "The Title is a mandatory Field")]
        public string Title { get; set; }
    }

    public sealed class GenericValidator<T>
    {
        /// <summary>
        /// Validates the specified entity.
        /// </summary>
        /// <param name="entity">The entity.</param>
        /// <returns></returns>
        public IList<ValidationResult> Validate(T entity)
        {
            var results = new List<ValidationResult>();
            var context = new ValidationContext(entity, null, null);
            Validator.TryValidateObject(entity, context, results,true);
            return results;
        }
    }
}