protected void btnOku_Click(object sender, EventArgs e)
        {
            Button btn = (Button)sender;
            int    ID  = Int32.Parse(btn.CommandArgument);

            string mesaj = "";

            Visitor visitor = (from v in db.Visitor where v.ID == ID select v).FirstOrDefault();

            lblKonu.Text = visitor.Subject;
            for (int i = 0; i < visitor.Message.Length; i++)
            {
                mesaj += visitor.Message[i];
                if (i % 40 == 0 && i != 0)
                {
                    mesaj += "</br>";
                }
            }
            lblMesaj.Text = mesaj;

            visitor.Readed = true;
            _visitorService.Update(visitor);

            ClientScript.RegisterStartupScript(this.GetType(), "alert", "ShowPopup();", true);
        }