private void SaveExecute(object obj)
 {
     try
     {
         Queue <tblClinicMaintenance> queue = Service.Service.GetMaintenanceQueue();
         string message;
         //just for adding new items
         if (!isEditingWindow)
         {
             message = "Clinic Maintenance has been added.";
             //if there is already 3 services, remove first one, then continue with adding
             if (queue != null && queue.Count == 3)
             {
                 tblClinicMaintenance deleteThis = queue.Dequeue();
                 Service.Service.DeleteMaintenance(deleteThis);
                 string content = "Clinic Maintenance id: " + deleteThis.maintenanceId + " has been deleted";
                 LogIntoFile.getInstance().PrintActionIntoFile(content);
             }
         }
         else
         {
             message = "Clinic Maintenance has been updated.";
         }
         tblClinicMaintenance maintenance = Service.Service.AddMaintenance(newMaintenance);
         if (maintenance != null)
         {
             MessageBox.Show(message);
             isUpdated = true;
             LogIntoFile.getInstance().PrintActionIntoFile(message + "Id: " + maintenance.maintenanceId);
             main.Close();
         }
     }
     catch (Exception ex)
     {
         MessageBox.Show(ex.ToString());
     }
 }