Bug 336684 [JFace] NPE in Tray Dialog
bundles/org.eclipse.jface/src/org/eclipse/jface/dialogs/TrayDialog.java
toolBar.addDisposeListener(new DisposeListener() {
			public void widgetDisposed(DisposeEvent e) {
				cursor.dispose();
			}
		});		
        fHelpButton = new ToolItem(toolBar, SWT.CHECK);
		fHelpButton.setImage(image);
		fHelpButton.setToolTipText(JFaceResources.getString("helpToolTip")); 
		fHelpButton.addSelectionListener(new SelectionAdapter() {
            public void widgetSelected(SelectionEvent e) {
				helpPressed();
            }
        });
		return toolBar;
	}
	/*
	 * Creates a help link. This is used when there is no help image
	 * available.
	 */
	private Link createHelpLink(Composite parent) {
		Link link = new Link(parent, SWT.WRAP | SWT.NO_FOCUS);
        ((GridLayout) parent.getLayout()).numColumns++;
		link.setLayoutData(new GridData(GridData.HORIZONTAL_ALIGN_CENTER));
		link.setText("<a>"+IDialogConstants.HELP_LABEL+"</a>"); 
		link.setToolTipText(IDialogConstants.HELP_LABEL);
		link.addSelectionListener(new SelectionAdapter() {
            public void widgetSelected(SelectionEvent e) {
				helpPressed();
            }
        });