public static void UpdateLastAccessedDate(string phoneNumber)
        {
            LData.DBDataContext db = new DBDataContext(Constants.AppConnectionString);

            //Get the record from db
            LData.PhoneUser user = db.PhoneUsers.FirstOrDefault(p => p.PhoneNumber == phoneNumber);

            if (user != null)
            {
                user.DateLastAccessed = DateTime.Now;
                db.SubmitChanges();
            }
        }
        public static void SaveUserPrefs(string phoneNumber, int zipCode, string keyWords)
        {
            LData.DBDataContext db = new DBDataContext(Constants.AppConnectionString);

            //Get the record from db
            LData.PhoneUser user = db.PhoneUsers.FirstOrDefault(p => p.PhoneNumber == phoneNumber);

            if (user != null)
            {
                user.ZipCode  = zipCode;
                user.KeyWords = keyWords;

                db.SubmitChanges(); //save back to db
            }
        }
        public static void GetUserPrefs(string phoneNumber, out int zipCode, out string keyWords)
        {
            zipCode  = 0;
            keyWords = "";

            LData.DBDataContext db = new DBDataContext(Constants.AppConnectionString);

            //Get the record from db
            LData.PhoneUser user = db.PhoneUsers.FirstOrDefault(p => p.PhoneNumber == phoneNumber);

            if (user != null)
            {
                zipCode  = user.ZipCode == null ? 0 : (int)user.ZipCode;
                keyWords = user.KeyWords;
            }
        }