private void onOK() {
		HashSet<Attribute> left = new HashSet<Attribute>();
		HashSet<Attribute> right = new HashSet<Attribute>();

		for (int i = 0; i < 6; i++) {
			for (int j = 0; j < 2; j++) {
				Attribute e = (Attribute) boxes.get(i * 2 + j).getSelectedItem();
				if (!(e instanceof EmptyAttribute)) {
					if (j == 0) {
						left.add(e);
					} else {
						right.add(e);
					}
				}
			}
		}

		// remove all attributes which would define themselves
		//right.removeAll(left);

		if (left.size() > 0 && right.size() > 0) {
			gui.currentModel.deps.add(new FunctionalDependency(left, right));
			gui.refreshWorkspace();
		}

		dispose();
	}