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
* @see
	 * org.eclipse.ui.IWorkbenchPart#createPartControl(org.eclipse.swt.widgets
	 * .Composite)
	 */
	public void createPartControl( Composite parent )
	{
		super.createPartControl( parent );
		Control[] children = parent.getChildren( );
		control = children[children.length - 1];
	}
	public boolean onBroughtToTop( IReportEditorPage page )
	{
		String prompt = ReportPlugin.getDefault( )
				.getPreferenceStore( )
				.getString( ReportPlugin.LIBRARY_WARNING_PREFERENCE );
		if ( prompt == null
				|| ( !ReportPlugin.getDefault( )
						.getPreferenceStore( )
						.getString( ReportPlugin.LIBRARY_WARNING_PREFERENCE )
						.equals( MessageDialogWithToggle.NEVER ) ) )
		{
			MessageDialogWithToggle dialog = MessageDialogWithToggle.openInformation( UIUtil.getDefaultShell( ),
					Messages.getString( "LibraryLayoutEditorFormPage.warning.title" ), 
					Messages.getString( "LibraryLayoutEditorFormPage.warning.message" ), 
					Messages.getString( "LibraryLayoutEditorFormPage.warning.prompt" ), 
					false,
					ReportPlugin.getDefault( ).getPreferenceStore( ),
					ReportPlugin.LIBRARY_WARNING_PREFERENCE );
			
			if ( dialog.getToggleState( ) )