Silverlight enabled WCF problem

 [ServiceContract(Namespace = "")]
    [AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
    public class Service1
    {
        [OperationContract]
        public void DoWork()
        {
            return;
        }

  	public List<Products> GetProducts()
        {
            List<Products> products = new List<Products>();
            string connString = "Data Source=(Local);Initial Catalog=Products;User Id=pig;Password=123456;";
            SqlConnection sqlConn = new SqlConnection(connString);
            SqlDataAdapter thisAdapter = new SqlDataAdapter("select * from [Products].[dbo].[Products]", sqlConn);
            DataSet thisDataSet = new DataSet();
            thisAdapter.Fill(thisDataSet, "Products");
            foreach (DataRow theRow in thisDataSet.Tables["Products"].Rows)
            {
                Products product = new Products();
                product.Id = theRow["Id"].ToString();
                product.Price = theRow["Price"].ToString();
                products.Add(product);
            }
            return products;
        }
    }

it shows a exception ：
The remote server returned an error: NotFound.

what's wrong???