private void populateData()
{
List <TimeSlot> timeSlotsArray = new List <TimeSlot>();
timeSlotsArray = timeSlotService.getAllTimeSlots();
foreach (TimeSlot timeSlot in timeSlotsArray)
{
dataGridTimeSlots.Rows.Add(timeSlot.Id, timeSlot.StHours + " : " + timeSlot.StMinutes, timeSlot.EtHours + " : " + timeSlot.EtMinutes, timeSlot.Duration);
}
}