Bug 259954 [Import/Export] Warning should be displayed when no projects are available in the archive/directory
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/wizards/datatransfer/WizardProjectsImportPage.java
private static String previouslyBrowsedArchive = ""; 
	private Button projectFromDirectoryRadio;
	private Button projectFromArchiveRadio;
	private Text archivePathField;
	private Button browseDirectoriesButton;
	private Button browseArchivesButton;
	private IProject[] wsProjects;
	
	private static final String[] FILE_IMPORT_MASK = {
			"*.jar;*.zip;*.tar;*.tar.gz;*.tgz", "*.*" }; 
	
	private String lastPath;
	
	
	private long lastModified;
	/**
	 * Creates a new project creation wizard page.
	 * 
	 */
	public WizardProjectsImportPage() {
		this("wizardExternalProjectsPage"); 
	}
	/**
	 * Create a new instance of the receiver.
	 * 
	 * @param pageName
	 */
	public WizardProjectsImportPage(String pageName) {
		super(pageName);
		setPageComplete(false);