/// <summary>
        /// Creates a hashset of the staff members current availabilities for the chosen day.
        /// </summary>
        /// <param name="thisDate"></param>
        /// <returns></returns>
        private HashSet <currentAvailItem> getCurrentAvails(DateTime thisDate)
        {
            HashSet <currentAvailItem> theseAvails = new HashSet <currentAvailItem>();

            try
            {
                HashSet <CurrentAvailabilities> currentAvailabilities = db.CurrentAvailabilities
                                                                        .Where(CA => CA.StaffId == thisStaff.Id)
                                                                        .Where(CA => CA.BlockStartTime.Date == thisDate.Date)
                                                                        .ToHashSet();



                foreach (CurrentAvailabilities thisAvailability in currentAvailabilities)
                {
                    currentAvailItem thisAvailItem = new currentAvailItem(thisAvailability);

                    theseAvails.Add(thisAvailItem);
                }
            }
            catch (Exception e)
            {
                Debug.WriteLine("Error getting current availabilities: " + e);
            }


            return(theseAvails);
        }
        //MARK: SETTING AN EXISTING AVAILABILITY

        /// <summary>
        /// The user selectes an existing availability
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        private void ExistingAvailsCB_SelectionChanged(object sender, SelectionChangedEventArgs e)
        {
            usingExistingAvailability = true;
            NewSchedETCB.IsEnabled    = true;
            NewSchedSTCB.IsEnabled    = true;

            currentAvailItem thisExistingAvailability = (currentAvailItem)ExistingAvailsCB.SelectedItem;

            existingAvailability = thisExistingAvailability.thisAvailability;

            if (newScheduleItem != null)
            {
                newScheduleItem.AvailabilityId = existingAvailability.Id;
                newScheduleItem.BlockStartTime = existingAvailability.BlockStartTime;
                newScheduleItem.BlockEndTime   = existingAvailability.BlockEndTime;
            }
        }