public FullTimeWorker createFullTimeWorker(String name, Date hireDate, int vacation,
			float sallary, float pension)
	{
		try
		{
			begin();
			FullTimeWorker worker = new FullTimeWorker(name, hireDate, vacation, sallary, pension);
			manager.persist(worker);
			commit();
			
			return worker;
		}
		catch(PersistenceException e)
		{
			e.printStackTrace();
			rollback();
			throw e;
		}
	}