private ImageIcon createNavigationIcon(String imageName, String altText) {
        ImageIcon icon = null;
        //Look for the image.
        String imgLocation = "images/"+imageName+".gif";
        URL imageURL = getClass().getResource(imgLocation);
            
        if(imageURL != null) {
            icon = new ImageIcon(imageURL, altText);
            
        } else {
            
            System.err.println("Resource not found: "+imgLocation);
        }        
        
        return icon;
        
    }