// This event handler is fired when the unassign employee button is clicked. It unassigns the chosen employee from the chosen activity.
 private void BtnUnassignEmployee_Click(object sender, RoutedEventArgs e)
 {
     try
     {
         if (dgScheduledEmployees.SelectedItem == null)
         {
             MessageBox.Show("You must select a scheduled employee.");
             return;
         }
         if (_scheduleManager.DeactivateSchedule(((PersonScheduleVM)dgScheduledEmployees.SelectedItem).ScheduleID))
         {
             MessageBox.Show("You have Unassigned " + ((PersonScheduleVM)dgScheduledEmployees.SelectedItem).FirstName + " " + ((PersonScheduleVM)dgScheduledEmployees.SelectedItem).LastName + " from " + ((ActivityVM)dgAllActivities.SelectedItem).ActivityName);
             //populateAllActivities();
             populateAllEmployees();
             populateEmployeesScheduled();
         }
     }
     catch (Exception ex)
     {
         MessageBox.Show(ex.Message + "\n\n" + ex.InnerException.Message);
     }
 }
        // This event handler is fired when the cancel activity button is pushed. It will allows the user to cancel
        // an activity they have previously signed up for
        private void BtnCancelActivity_Click(object sender, RoutedEventArgs e)
        {
            if (dgUserVolunteerActivities.SelectedItem == null)
            {
                MessageBox.Show("You must make a volunteering selection.");
                return;
            }

            if (MessageBox.Show("Are you sure?", "Cancel Volunteering", MessageBoxButton.YesNo, MessageBoxImage.Warning) == MessageBoxResult.Yes)
            {
                try
                {
                    if (_scheduleManager.DeactivateSchedule(((ActivityVM)dgUserVolunteerActivities.SelectedItem).ScheduleID))
                    {
                        MessageBox.Show("Volunteering Canceled.");
                        populateUserVolunteerActivities();
                    }
                }
                catch (Exception ex)
                {
                    MessageBox.Show(ex.Message + "\n\n" + ex.InnerException.Message);
                }
            }
        }