@Override
	public int delCommentOnResource(int resourceCreatorID, int resourceID,
			int manipulationID) {
		if(resourceCreatorID < 0 || manipulationID < 0 || resourceID < 0)
			return -1;
		session = sessionFactory.openSession();
		try {
			tx = session.beginTransaction();
			
			List<MANIPULATIONS> obj= session.createCriteria(MANIPULATIONS.class)
					.add(Restrictions.and(Restrictions.eq("mid",Integer.toString(manipulationID)),
							Restrictions.eq("rid", Integer.toString(resourceID))))
					.list();
			
			for (MANIPULATIONS m: obj){
				session.delete("MANIPULATIONS", m);
			
			System.out.println("Deleted comment with ID "+ manipulationID+" on resource "+resourceID+".");
			}
			tx.commit();
			return 0;
		}catch (Exception e) {
			e.printStackTrace(System.out);
			return -1;
		}finally{
			session.close();
		}
	}