private void btnAdd_Click(object sender, EventArgs e)
 {
     try
     {
         FormStaffDetails staffDetailsForm = new FormStaffDetails(stfList);
         staffDetailsForm.Show();
     }
     catch (Exception ex)
     {
     }
 }
        private void dgvStaffList_DoubleClick(object sender, EventArgs e)
        {
            try
            {
                if (dgvStaffList.SelectedCells.Count != 0)
                {
                    int   staffID    = Convert.ToInt32(dgvStaffList.SelectedCells[0].Value);
                    Staff foundStaff = stfList.Find(el => el.Id == staffID);

                    double minSalary = calculateSalary(foundStaff);

                    FormStaffDetails staffDetailsForm = new FormStaffDetails(stfList, foundStaff, minSalary);
                    staffDetailsForm.Show();
                }
            }
            catch (Exception ex)
            {
                //TODO Log this exception.
            }
        }