my script dont work (global.asax)

    void Application_Start(object sender, EventArgs e) 
    {



        if (Convert.ToBoolean(Session["AppStartStatus"]) == true)
        {

            // Code that runs on application startup
            // Warranty Automation Application
            SqlConnection conGlobal = new SqlConnection
                      (@"Data Source=.\SQLEXPRESS;AttachDbFileName=|DataDirectory|\TRANE.mdf;Integrated Security=True;User Instance=True");

            conGlobal.Open();

            string selService;
            selService = "Select * From ServiceLink WHERE DatetimeSched='" + DateTime.Now.ToShortDateString() + "'";

            SqlCommand globalCom = new SqlCommand(selService, conGlobal);


            SqlDataReader globalReader = globalCom.ExecuteReader();


            if (globalReader.HasRows)
            {

                while (globalReader.Read())
                {

                    string affectedserials;

                    affectedserials = globalReader["UnitSerial"].ToString();

                    //create the mail message
                    MailMessage mail = new MailMessage();

                    //set the addresses
                    mail.From = new MailAddress("[email protected]");
                    mail.To.Add("[email protected]");
                    // the password for both email addresses is "new12345@"


                    //set the content
                    mail.Subject = "Service Notification";
                    mail.Body = "A Product with Serial#: " + affectedserials.ToString() + " needs a service visit. Please check the Service Link records right away";

                    //send the message
                    SmtpClient smtp = new SmtpClient();
                    smtp.EnableSsl = true;
                    smtp.Send(mail);



                }

                globalReader.Close();
                string updateDate;
                updateDate = "UPDATE ServiceLink SET DatetimeSched = '" + DateTime.Now.AddMonths(6).ToShortDateString() + "' WHERE DatetimeSched = '" + DateTime.Now.ToShortDateString() + "'";
                SqlCommand comDateupdate = new SqlCommand(updateDate, conGlobal);
                comDateupdate.ExecuteNonQuery();


            }
        }
        else if (Convert.ToBoolean(Session["AppStartStatus"]) == false)
        {

            //create the mail message
            MailMessage mail = new MailMessage();

            //set the addresses
            mail.From = new MailAddress("[email protected]");
            mail.To.Add("[email protected]");
            // the password for both email addresses is "new12345@"


            //set the content
            mail.Subject = "Service Notification";
            mail.Body = "Service Link is disabled.";

            //send the message
            SmtpClient smtp = new SmtpClient();
            smtp.EnableSsl = true;
            smtp.Send(mail);

        }
        else if (Session["AppStartStatus"] == null)
        {
            //Make AppStart Status By default true
            Session["AppStartStatus"] = true;
        }
        
    }