public Response isUserExist(string userId)
        {
            Response retval = new IsExistResponseError(false);

            try
            {
                var dataSet = _dal.GetUser(userId);
                if (dataSet.Tables[0].Rows.Count != 0)
                {
                    retval = new IsExistResponseOk(true);;
                }
            }
            catch (Exception ex)
            {
                new AppResponseError(ex.Message);
            }
            return(retval);
        }
        public Response Register(RegisterRequest request)
        {
            Response retval = new RegisterResponseOk("You registered successfuly");

            try
            {
                // first check if user exist
                var ds = _dal.GetUser(request.Login.UserIdEmail);
                if (ds.Tables[0].Rows.Count == 0)
                {
                    _dal.CreateUser(request);
                }
                else
                {
                    retval = new RegisterResponseUserExist("User exist");
                }
            }
            catch (Exception ex)
            {
                retval = new AppResponseError(ex.Message);
            }
            return(retval);
        }