Try replacing:
Code:
command.CommandText = "INSERT INTO Visitor(Referer, Browser) VALUES(@Referer, @Browser);";
command.CommandType = CommandType.StoredProcedure;
command.Parameters.Add("@Referer", (Request.UrlReferrer == null ? "none" : Request.UrlReferrer.ToString()));
command.Parameters.Add("@Browser", Request.UserAgent);
with:
Code:
command.CommandText = "INSERT INTO Visitor(Referer, Browser) VALUES(" + (Request.UrlReferrer == null ? "none" : Request.UrlReferrer.ToString()) + "," + Request.UserAgent + ");";
command.CommandType = CommandType.Text;