Fail To Get Return_Value In Stored Procedure NullValueReference

I have a stored procedure that insert into a table and return a value indicating if the insert really occured.
If the a insert occurs then it returns the identity of that insert.

I have slimmed down my code here, so you can see.
My problem is that a NullValueReference exceptions occurs when trying to reference the returnvalue.
Is it not possible to get a return value along with a recordset ?

public int RegisterCustomer(Customer customer)

{

SqlCommand myCommand = new SqlCommand("ins_RegistrerKunde", myConnection);

myCommand.CommandType = CommandType.StoredProcedure;

SqlParameter Epost = new SqlParameter("@Epost", SqlDbType.VarChar, 25);

SqlParameter Passord = new SqlParameter("@Passord", SqlDbType.VarChar, 25);

SqlParameter ReturnValue = new SqlParameter("@RETURN_VALUE", SqlDbType.Int, 4);

ReturnValue.Direction = ParameterDirection.ReturnValue;

Epost.Value = customer.Email;

Passord.Value = customer.Password;

myCommand.Parameters.Add(ReturnValue);

myCommand.Parameters.Add(Epost);

myCommand.Parameters.Add(Passord);

myConnection.Open();

SqlDataReader result = myCommand.ExecuteReader(CommandBehavior.SingleRow);

int isRegistered = (int)myCommand.Parameters["@RETURN_VALUE"].Value;

myConnection.Close();

if (isRegistered == 1)

{

result.Read();

return Convert.ToInt32(result["Kunde_ID"]);

result.Close();

}

return Convert.ToInt32(isRegistered);

}

 

//Stored Procedure ins_RegistrerKunde
create procedure %PROC% (@Epost varchar(25), @Passord varchar(25))
as
begin
IF EXISTS(  SELECT Epost FROM tbl_Kunde WHERE Epost = @Epost)
    RETURN 0
ELSE
    INSERT INTO tbl_Kunde( Epost, Passord)
    VALUES (@Epost, @Passord)
    SELECT @@IDENTITY AS Kunde_ID
    RETURN 1
end
go