ทำไมเมื่อผมกดเซฟข้อมูล จึงมี popup หน้าเดียวกันเกิดขึ้นมา โดยที่ไม่ได้เขียนเลยแม้แต่น้อย

 protected void btnSave_Click(object sender, ImageClickEventArgs e)
    {
        FilterPaymentVoucherWHT objPayment = new FilterPaymentVoucherWHT();

        objPayment.WHTCode = txt01PatmentVoucherNo.Text;
        objPayment.WHTDate = txt01PaymentDate.Text;
        objPayment.WHTSupName = txt01Name.Text;
        objPayment.WHTPersonTaxId = txt01PersonIDNo.Text;
        objPayment.WHTCompanyTaxId = txt01TaxIDNo.Text;
        objPayment.WHTAddress = txt01address.Text;
        objPayment.WHTType = txt01TypesOfFunds.Text;
        objPayment.WHTRate = (float)Convert.ToDouble(txt01TaxRate.Text);
        objPayment.WHTAmount = (float)Convert.ToDouble(txt01Amount.Text);
        objPayment.WHTTax = (float)Convert.ToDouble(txt01CostOfTax.Text);
        if (rbt01PND1G.Checked) objPayment.WHTGroup = 1;
        else if (rbt01PND1GS.Checked) objPayment.WHTGroup = 2;
        else if (rbt01PND2.Checked) objPayment.WHTGroup = 3;
        else if (rbt01PND2G.Checked) objPayment.WHTGroup = 4;
        else if (rbt01PND3.Checked) objPayment.WHTGroup = 5;
        else if (rbt01PND3G.Checked) objPayment.WHTGroup = 6;
        else if (rbt01PND53.Checked) objPayment.WHTGroup = 7;
        if (rbt01TaxWithHolding.Checked) objPayment.WHTPayType = 1;
        else if (rbt01TaxForever.Checked) objPayment.WHTPayType = 2;
        else if (rbt01OneTimeTax.Checked) objPayment.WHTPayType = 3;
        else if (rbt01Other.Checked) objPayment.WHTPayType = 4;
        objPayment.payVoucherDocNo = "2";

        if (hdMode.Value.ToString() == "U")
        {
            result = svPayment.updatePaymentVoucherWHT(objPayment, sCompanyCode);

        }
        else 
        {        
            result = svPayment.insertPaymentVoucherWHT(objPayment, sCompanyCode);       
        }
        hdMode.Value = "I";

    }