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
fManifestFileBrowseButton= new Button(manifestFileGroup, SWT.PUSH);
		fManifestFileBrowseButton.setText(JarPackagerMessages.getString("JarManifestWizardPage.manifestFileBrowse.text")); 
		fManifestFileBrowseButton.setLayoutData(new GridData(GridData.HORIZONTAL_ALIGN_FILL));
		fManifestFileBrowseButton.addSelectionListener(new SelectionAdapter() {
			public void widgetSelected(SelectionEvent e) {
				handleManifestFileBrowseButtonPressed();
			}
		});
	}
	/**
	 * Creates the JAR sealing specification controls.
	 *
	 * @param parent the parent control
	 */
	protected void createSealingGroup(Composite parent) {
		
		Composite sealingGroup= new Composite(parent, SWT.NONE);
		GridLayout layout= new GridLayout();
		layout.numColumns= 3;
		layout.horizontalSpacing += 3;
		sealingGroup.setLayout(layout);
		sealingGroup.setLayoutData(new GridData(GridData.HORIZONTAL_ALIGN_FILL | GridData.VERTICAL_ALIGN_FILL));
		createSealJarGroup(sealingGroup);
		createSealPackagesGroup(sealingGroup);
		
	}
	/**
	 * Creates the JAR sealing specification controls to seal the whole JAR.
	 *