Is it possible to keep a Windows Form inside a XNA project? I tried it but without success.

Below I'm showing how my main file is.

using System;

namespace JogoSuecaOnline
{
#if WINDOWS || XBOX
    static class Program
    {
        /// <summary>
        /// The main entry point for the application.
        /// </summary>
        static void Main(string[] args)
        {
            MainMenu menu = new MainMenu();
            menu.Show();
        }
    }
#endif
}