private void addNavigationMenu() {
		String[] buttonLabels = {"Intro", "Pixels", "Colors", "Data in Images", "False Color", "Check Color", "About"};
		
		int width = mainDisplay.getWidth();
		int buttonWidth = 120;
		int buttonHeight = 40;
		int padding = (width-(buttonLabels.length*buttonWidth))/(buttonLabels.length+1);
		
		GridLayout layout = new GridLayout(1, buttonLabels.length);
		System.out.println(padding);
		layout.setHgap(padding);
		
		Container north = new Container();
		north.setLayout(layout);
		
		for (int i=0; i < buttonLabels.length; i++) {
			JButton btn = new JButton(buttonLabels[i]);
			btn.setSize(buttonWidth, buttonHeight);
			btn.addActionListener(new ActionListener() {
				@Override
				public void actionPerformed(ActionEvent arg0) {
					mode = getMode(((JButton)arg0.getSource()).getText());
					redisplay();
				}
				private Mode getMode(String text) {
					if (text.equals("Intro"))
						return Mode.INTRODUCTION;
					 else if (text.equals("Pixels")) 
						 return Mode.PIXELS;
					 else if (text.equals("Colors"))
						 return Mode.COLORS;
					 else if (text.equals("Data in Images"))
						 return Mode.DATA_IN_IMAGES;
					 else if (text.equals("False Color"))
						 return Mode.FALSE_COLOR;
					 else if (text.equals("Check Color"))
						 return Mode.CHECK_COLOR;
					 else if (text.equals("About"))
						 return Mode.ABOUT;
					 else 
						 return null;
				}
			});
			north.add(btn);
		}
		mainDisplay.add(north, BorderLayout.NORTH);
	}