search หาข้อมูลค่ะ ติดที่มีหาแบบวันที่ ค่ะ มีการใส่ if ในการหา ทำให้ หาอื่นไม่สามารถหาได้ asp.net c#

string StrConn = WebConfigurationManager.ConnectionStrings["BaseMungthai"].ToString();
            SqlConnection Conn = new SqlConnection(StrConn);
            Conn.Open();
            string sqlProduct;

              if (TextBox14.Text.Trim() != "")
             {
                 DateTime date1 = DateTime.ParseExact(TextBox14.Text, "d/M/yyyy", new System.Globalization.CultureInfo("th-TH"));


                 DateTime date2 = DateTime.ParseExact(TextBox15.Text, "d/M/yyyy", new System.Globalization.CultureInfo("th-TH"));
                 
  
             sqlProduct = " SELECT tbDCusCardS.CardSNo, tbMAgent.AgentCode, tbMAgent.AgentName, tbMCardS.SaveDate, tbMCardS.SendDate, tbTempInsurerance.InsurNo FROM tbDCusCardS INNER JOIN tbMCardS ON tbDCusCardS.CardFID = tbMCardS.CardFID INNER JOIN tbMAgent ON tbDCusCardS.AgentID = tbMAgent.AgentID INNER JOIN tbTempInsurerance ON tbDCusCardS.InsuID = tbTempInsurerance.InsuID WHERE (tbDCusCardS.CardSNo between  '" + TextBox12.Text + "' AND '" + TextBox13.Text + "') OR  tbTempInsurerance.InsurNo  ='" + TextBox16.Text + "'(tbMCardS.SaveDate between convert(datetime, '" + string.Format("{0}/{1}/{2}", date1.Month, date1.Day, date1.Year) + "', 101) AND  convert(datetime, '" + string.Format("{0}/{1}/{2}", date2.Month, date2.Day, date2.Year) + "', 101))" ";
             SqlDataAdapter da = new SqlDataAdapter(sqlProduct, Conn);
             DataSet ds = new DataSet();
             da.Fill(ds, "tbDCusCardS");
             GridAO.DataSource = ds.Tables["tbDCusCardS"];
             GridAO.DataBind();

            }