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
fReuseManifestCheckbox.addListener(SWT.MouseUp, fUntypedListener);
			
			createNewManifestFileGroup(saveOptions);
		fUseManifestRadioButton= new Button(fManifestGroup, SWT.RADIO | SWT.LEFT);
		fUseManifestRadioButton.setText(JarPackagerMessages.getString("JarManifestWizardPage.useManifest.text")); 
		
		fUseManifestRadioButton.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));
			Composite existingManifestGroup= new Composite(fManifestGroup, SWT.NONE);
			GridLayout existingManifestLayout= new GridLayout();
			existingManifestLayout.marginWidth= 0;
			existingManifestGroup.setLayout(existingManifestLayout);
			data= new GridData(GridData.HORIZONTAL_ALIGN_FILL | GridData.VERTICAL_ALIGN_FILL | GridData.GRAB_HORIZONTAL);
			data.horizontalIndent=20;
			existingManifestGroup.setLayoutData(data);
			createManifestFileGroup(existingManifestGroup);
	}
	protected void createNewManifestFileGroup(Composite parent) {
		
		Composite manifestFileGroup= new Composite(parent, SWT.NONE);
		GridLayout layout= new GridLayout();
		layout.marginWidth= 0;
		layout.numColumns= 3;
		manifestFileGroup.setLayout(layout);
		manifestFileGroup.setLayoutData(new GridData(GridData.HORIZONTAL_ALIGN_FILL | GridData.VERTICAL_ALIGN_FILL | GridData.GRAB_HORIZONTAL));
		fNewManifestFileLabel= new Label(manifestFileGroup, SWT.NONE);
		fNewManifestFileLabel.setText(JarPackagerMessages.getString("JarManifestWizardPage.newManifestFile.text")); 
		
		fNewManifestFileText= new Text(manifestFileGroup, SWT.SINGLE | SWT.BORDER);
		fNewManifestFileText.addListener(SWT.Modify, fUntypedListener);