/// <summary>
 /// Fills the listbox with employees that are currently scheduled for that shift.
 /// </summary>
 /// <param name="toAddToShift"></param>
 private void AddEmployeeListToShift(List <Employee> toAddToShift)
 {
     dataGridViewScheduling.Rows.Clear();
     dataGridViewScheduling.Refresh();
     foreach (Employee e in toAddToShift)
     {
         int             rowId = dataGridViewScheduling.Rows.Add();
         DataGridViewRow row   = dataGridViewScheduling.Rows[rowId];
         row.Cells["id"].Value        = e.Id;
         row.Cells["firstName"].Value = e.FirstName;
         row.Cells["surName"].Value   = e.SurName;
     }
     foreach (DataGridViewRow row in dataGridViewScheduling.Rows)
     {
         int employeeid = Convert.ToInt32(row.Cells["id"].Value);
         int nrofshifts = employeeStorage.CheckNrOfShifts(employeeid, this.date.Date.ToString("yyyy-MM-dd"));
         if (nrofshifts > 2)
         {
             row.DefaultCellStyle.BackColor = Color.Red;
         }
     }
 }