Online Circular Chess in Silverlight, ASP.NET AJAX, WCF Web Services, and LINQ to SQL

using System;

namespace CChess
{
    public enum ChessPieceTypes : byte
    {
        Pawn = 1,

        King,

        Queen,

        Rook,

        Knight,

        Bishop
    }

    public class CChessPiece
    {
        /// <summary>
        /// For serializing
        /// </summary>
        private CChessPiece() { }

        public CChessPiece(byte id, ChessPieceTypes type, CChessColors color, CChessSquare square)
        {
            _id = id;
            _type = type;
            _color = color;
            _square = square;
        }

        private byte _id;
        private ChessPieceTypes _type;
        private CChessSquare _square;
        private CChessColors _color;

        public byte ID
        {
            get { return _id; }
        }

        public ChessPieceTypes Type
        {
            get { return _type; }
            set
            {
                if (_type == ChessPieceTypes.Pawn && value != ChessPieceTypes.King && value != ChessPieceTypes.Pawn)
                {
                    _type = value;
                }
                else
                {
                    throw new Exception("Invalid promotion");
                }
            }
        }

        public CChessColors Color
        {
            get { return _color; }
        }

        public bool IsAlive
        {
            get { return (_square != null); }
        }

        /// <summary>
        /// Gets or sets the square in which this piece currently is.
        /// </summary>
        public CChessSquare Square
        {
            get { return _square; }
            set { _square = value; }
        }
    }
}