Bug 315745 Two message pop up when switch from XML source to layout.[01]
UI/org.eclipse.birt.report.designer.ui.lib/src/org/eclipse/birt/report/designer/ui/editors/LibraryLayoutEditorFormPage.java
import org.eclipse.birt.report.designer.nls.Messages;
import org.eclipse.birt.report.designer.ui.ReportPlugin;
import org.eclipse.birt.report.designer.ui.views.attributes.AttributeViewPage;
import org.eclipse.birt.report.model.api.ModuleHandle;
import org.eclipse.birt.report.model.api.activity.ActivityStackEvent;
import org.eclipse.birt.report.model.api.activity.ActivityStackListener;
import org.eclipse.gef.GraphicalViewer;
import org.eclipse.jface.dialogs.MessageDialogWithToggle;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.ui.IEditorInput;
import org.eclipse.ui.IEditorSite;
import org.eclipse.ui.PartInitException;
import org.eclipse.ui.forms.IManagedForm;
import org.eclipse.ui.forms.editor.FormEditor;
import org.eclipse.ui.part.MultiPageEditorSite;
/**
 * 
 */
public class LibraryLayoutEditorFormPage extends LibraryLayoutEditor implements
		IReportEditorPage
{
	public static final String ID = "org.eclipse.birt.report.designer.ui.editors.library.layout"; 
	private int index;
	private FormEditor editor;
	private Control control;
	private int staleType;
	private ActivityStackListener commandStackListener = new ActivityStackListener( ) {
		public void stackChanged( ActivityStackEvent event )
		{