How to insert records into NAV from Visual Studio

Below is a simple console application to create a customer record from the visual studio.

namespace ConsoleApplication1
{
    using Customer;
    class Program
    {
        static void Main(string[] args)
        {
            Customer_Service service = new Customer_Service();
            service.UseDefaultCredentials = true;
            Customer.Customer customer = new Customer.Customer() { No = "123491", Blocked = Blocked.Ship};
            service.Create(ref customer);
        }   
    }
}

This will insert customer record but Blocked field does not contains the correct value. This can be achieved by changing the line as below:

Customer.Customer customer = new Customer.Customer() { No = "123491", Blocked = Blocked.Ship, BlockedSpecified = true};

This is mostly required for all fields except the string type because I think web services request/responses are in xml and type conversions are required internally from string to other data type.