Bug 11437 jar packager: no error message but buttons disabled
20020314 on the 'jar manifest' wizard page, if you select to use existing manifest file there's no error message but next and finish are disabled user should be informed what to do to make the wizard happy
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/jarpackager/JarManifestWizardPage.java
* in the next instance of this page. Subclasses wishing to persist
	 * settings for their controls should extend the hook method 
	 * <code>internalSaveWidgetValues</code>.
	 */
	public final void saveWidgetValues() {
		IDialogSettings settings= getDialogSettings();
		if (settings != null) {
			
			settings.put(STORE_GENERATE_MANIFEST, fJarPackage.isManifestGenerated());
			settings.put(STORE_SAVE_MANIFEST, fJarPackage.isManifestSaved());
			settings.put(STORE_REUSE_MANIFEST, fJarPackage.isManifestReused());
			settings.put(STORE_MANIFEST_LOCATION, fJarPackage.getManifestLocation().toString());
			
			settings.put(STORE_SEAL_JAR, fJarPackage.isJarSealed());
			}
		
		internalSaveWidgetValues();
	}
	/**
	 * Hook method for subclasses to persist their settings.
	 */
	protected void internalSaveWidgetValues() {
	}
	/**
	 *	Hook method for restoring widget values to the values that they held
	 *	last time this wizard was used to completion.
	 */
	protected void restoreWidgetValues() {
		if (!fJarPackage.isUsedToInitialize())
			initializeJarPackage();