private void addPreferences() {
		selection = new ArrayList<ProjectMember>();
		for (Node n : display) {
			if (n.box.isSelected()) {
				selection.add(n.mem);
			}
		}
		
		int groupSize = Controller.project.getSizeOfTeams();

		if ((selection.size() > groupSize) && radioReq.isSelected()) {
			JOptionPane.showMessageDialog(getContentPane(), "You have selected too many people to work together.\nYou have limited your group size to " + groupSize + " members.\n\nPlease select " + groupSize + " or less members that have to work together.");
		}
		else if (((display.size() - selection.size()) < groupSize) && radioForbid.isSelected()) {
			JOptionPane.showMessageDialog(getContentPane(), "You have selected too many people who cannot work together.\nYou have indicated that your groups should have " + groupSize + " members.\n\nPlease select fewer members that cannot work together.");
		}
		else {
			if (radioReq.isSelected()) {
				Controller.project.addRequiredMembers(selection);
				clearSelection();
			}
			else if (radioForbid.isSelected()) {
				Controller.project.addForbiddenMembers(selection);
				clearSelection();
			}
			else {
				JOptionPane.showMessageDialog(getContentPane(), "Please indicate whether or not these members either have to or can not work together.");
			}
		}	
	}