private void buttonX2_Click(object sender, EventArgs e)
        {
            this.SaveConfig("sqlServerIPAddress", ip_serverip.Text);
            this.SaveConfig("sqlServerPort", int_port.Text);
            this.SaveConfig("dbUsername", tb_username.Text.Trim());
            this.SaveConfig("dbPassword", SysUtil.EncryptDES(tb_password.Text, "quality"));
            ConfigurationManager.RefreshSection("appSettings");
            frm_login login = new frm_login();

            login.Show();
            this.Close();
        }