public HelpDialog(BibtexBaseFrame bf) 
{
    // Initializes, but does not show the help dialog.
	super(bf, GUIGlobals.helpTitle, false);
	content = new HelpContent();
	content.addHyperlinkListener(this);
	setSize(GUIGlobals.helpSize);
	Dimension ds = GUIGlobals.helpSize, 
	    df = bf.getSetSize();
	Point pf = bf.getSetLocation();
	setLocation(new Point(Math.max(0,(pf.x+(df.width-ds.width)/2)),
	Math.max(0,(pf.y+(df.height-ds.height)/2))));
	/* There is probably no need for a window listener now, so it's commented out.
	diag.addWindowListener(new WindowAdapter() {
		public void windowClosing(WindowEvent e) {
		    open = null;
		}	       
	    });*/
	JToolBar tlb = new JToolBar();
	//tlb.add(new CloseAction());
	//tlb.addSeparator();
	tlb.add(back);
	tlb.add(forward);
	tlb.addSeparator();
	tlb.add(contents);
	tlb.setFloatable(false);
	// Make ESC close dialog, and set shortkeys for back and forward.
	InputMap im = tlb.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
	ActionMap am = tlb.getActionMap();
	im.put(GUIGlobals.exitDialog, "close");
	am.put("close", new CloseAction());
	im.put(GUIGlobals.switchPanelLeft, "left");
	am.put("left", back);
	im.put(GUIGlobals.switchPanelRight, "right");
	am.put("right", forward);
	// Set shortkeys for back and forward specifically for the EditorPane.
	im = content.getInputMap(JComponent.WHEN_FOCUSED);
	am = content.getActionMap();
	im.put(GUIGlobals.switchPanelLeft, "left");
	am.put("left", back);
	im.put(GUIGlobals.switchPanelRight, "right");
	am.put("right", forward);
	getContentPane().add(tlb, BorderLayout.NORTH);
	getContentPane().add(content.getPane());
	forward.setEnabled(false);
	back.setEnabled(false);
}

 public  void hyperlinkUpdate(HyperlinkEvent e) 
{
	if (e.getEventType() == HyperlinkEvent.EventType.ACTIVATED) {
	    content.setPage(e.getURL());
	    back.setEnabled(true);
	    forward.setEnabled(false);
	}
}

 public  void showPage(URL url) 
{
	if (!isVisible()) {
	    setVisible(true);
	    content.reset();
	    forward.setEnabled(false);
	    back.setEnabled(false);
	} else {
	    setVisible(true);
	    forward.setEnabled(false);
	    back.setEnabled(true);
	}
	content.setPage(url);
	content.requestFocus();
	//setVisible(true);
}