I cant validate my mvc registration form,

public partial class Registration

{

public int id { get; set; }

[Required(ErrorMessage = "Please enter name.")]

public string Name { get; set; }

public string Email { get; set; }

public string Gender { get; set; }

public string Phone { get; set; }

public string Address { get; set; }

}

public ViewResult Index()

{

return View();

}

[HttpGet]

public ViewResult RegistrationForm()

{

return View();

}

[HttpPost]

public ViewResult RegistrationForm(Registration registration)

{

string constr = ConfigurationManager.ConnectionStrings["DefaultConnection"].ConnectionString;

using (SqlConnection con = new SqlConnection(constr))

{

string query = "INSERT INTO Registration(Name, Email,Gender,Phone,Address) VALUES(@Name, @Email,@Gender,@Phone,@Address)";

using (SqlCommand cmd = new SqlCommand(query))

{

cmd.Connection = con;

con.Open();

cmd.Parameters.AddWithValue("@Name", registration.Name);

cmd.Parameters.AddWithValue("@Email", registration.Email);

cmd.Parameters.AddWithValue("@Gender", registration.Gender);

cmd.Parameters.AddWithValue("@Phone", registration.Phone);

cmd.Parameters.AddWithValue("@Address", registration.Address);

cmd.ExecuteNonQuery();

con.Close();

}

}

return View("Congratualation", registration);

}

@model WebApplication1.Models.Registration

@{

ViewBag.Title = "RegistrationForm";

}

@using (Html.BeginForm())

{

@Html.AntiForgeryToken()

}