private void cbxLaisuat_SelectedIndexChanged(object sender, EventArgs e)
        {
            Tinhlai frmTinhLai = new Tinhlai();

            if (edit == false)
            {
                return;
            }
            else
            {
                if (cbxLaisuat.Text == laisuat.ToString())
                {
                    return;
                }
                frmTinhLai.init(dbfile, txtMaHD.Text, int.Parse(cbxLaisuat.Text));
                frmTinhLai.ShowDialog();
                if (frmTinhLai.saved == false)
                {
                    cbxLaisuat.Text = laisuat.ToString();
                }
                else
                {
                    cmdClose.Enabled = false;
                }
            }
        }
        private void cbxLaisuat_Leave(object sender, EventArgs e)
        {
            Tinhlai frmTinhLai = new Tinhlai();
            int     laimoi;

            if (edit == false)
            {
                return;
            }
            else
            {
                if (cbxLaisuat.Text == oldLS)
                {
                    return;
                }
                laimoi = (int)(double.Parse(cbxLaisuat.Text) * 100);
                frmTinhLai.init(dbfile, txtMaHD.Text, laimoi);
                frmTinhLai.ShowDialog();
                if (frmTinhLai.saved == false)
                {
                    cbxLaisuat.Text = laisuat.ToString();
                }
            }
        }
 private void cbxLaisuat_SelectedIndexChanged(object sender, EventArgs e)
 {
     Tinhlai frmTinhLai = new Tinhlai();
     if (edit == false)
         return;
     else
     {
         if (cbxLaisuat.Text == laisuat.ToString())
             return;
         frmTinhLai.init(dbfile, txtMaHD.Text, int.Parse(cbxLaisuat.Text));
         frmTinhLai.ShowDialog();
         if (frmTinhLai.saved == false)
             cbxLaisuat.Text = laisuat.ToString();
         else
         {
             cmdClose.Enabled = false;
         }
     }
 }
 private void cbxLaisuat_Leave(object sender, EventArgs e)
 {
     Tinhlai frmTinhLai = new Tinhlai();
     int laimoi;
     if (edit == false)
         return;
     else
     {
         if (cbxLaisuat.Text == oldLS)
             return;
         laimoi = (int)(double.Parse(cbxLaisuat.Text) * 100);
         frmTinhLai.init(dbfile, txtMaHD.Text, laimoi);
         frmTinhLai.ShowDialog();
         if (frmTinhLai.saved == false)
             cbxLaisuat.Text = laisuat.ToString();
     }
 }