private void btnAdd_Click(object sender, EventArgs e)
        {
            //insert new record
            //read input
            DateTime date  = DateTime.Parse(txtDate.Text);
            double   hours = double.Parse(txtHours.Text);
            //call method
            EmployeeManager manager = new EmployeeManager();

            manager.AddNewWorkRecord(id, date, hours);
            MessageBox.Show("Record Added");
        }