private void vergebeIDs(IOManager manager)
	{
		manager.readRaeume();
		List<Raum> rlist = manager.getRaeume();
		Set<Integer> idList = new HashSet<Integer>();

		for(Raum r : rlist)
		{
			idList.add(r.getId());
		}

		Random rand = new Random();
		int newid;

		GridButton[][] buttons = _ui.getMap().getButtonArray();
		for(int y = 0; y < buttons[0].length; ++y)
		{
			for(int x = 0; x < buttons.length; ++x)
			{
				Raum raum = buttons[x][y].getRaum();
				if(raum != null && raum.getId() == 0)
				{
					do
					{
						newid = rand.nextInt();
					} while(newid == 0 || idList.contains(newid));

					raum.setId(newid);
					idList.add(newid);
				}
			}
		}
	}