Bug 8476 JAR Packager: Make main class field editable
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/jarpackager/JarManifestWizardPage.java
*/
	protected void updatePageCompletion() {
		boolean pageComplete= isPageComplete();
		setPageComplete(pageComplete);
		if (pageComplete) {
			setErrorMessage(null);
		}
	}
	
	/**
	 * Creates a file resource handle for the file with the given workspace path.
	 * This method does not create the file resource; this is the responsibility
	 * of <code>createFile</code>.
	 *
	 * @param filePath the path of the file resource to create a handle for
	 * @return the new file resource handle
	 * @see #createFile
	 */
	protected IFile createFileHandle(IPath filePath) {
		if (filePath.isValidPath(filePath.toString()) && filePath.segmentCount() >= 2)
			return JavaPlugin.getWorkspace().getRoot().getFile(filePath);
		else
			return null;
	}
	/**
	 * Creates a new label with a bold font.
	 *
	 * @param parent the parent control
	 * @param text the label text
	 * @return the new label control