private void bt_save_Click(object sender, EventArgs e)
        {
            try
            {
                this.Validate();
                this.tb_versioncode.DataBindings[0].WriteValue();
                Portable.UpdateVersion(this.filepath, this.password, vtbl);
            }
            catch (Exception e2)
            {
                MessageBox.Show(e2.Message);
            }
            try{
                Portable.UpdateVisitLogInfo(this.filepath, this.password, this.dataGridView1.DataSource as DataTable);
                MessageBox.Show("Attendance updated successfully");
            }

            catch (Exception e1)
            {
                MessageBox.Show(e1.Message);
            }
        }