Bug 41927 [Dialogs] Selecting in PreferenceDialog generates too many invalid entries
20030825 If you select an entry, close the dialog and then reopen it selecting anotehr entry will result in a "this page has invalid values" although you selected nothing.
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferencePage.java
updateApplyButton();
		}
	}
	/**
	 * Returns a string suitable for debugging purpose only.
	 */
	public String toString() {
		return getTitle();
	}
	/**
	 * Updates the enabled state of the Apply button to reflect whether 
	 * this page is valid.
	 */
	protected void updateApplyButton() {
		if (applyButton != null)
			applyButton.setEnabled(isValid());
	}
	/**
	 * Creates a composite with a highlighted Note entry and a message text.
	 * This is designed to take up the full width of the page.
	 * 
	 * @param font the font to use
	 * @param composite the parent composite
	 * @param title the title of the note
	 * @param message the message for the note
	 * @return the composite for the note
	 */
	protected Composite createNoteComposite(
		Font font,
		Composite composite,