Bug 390669 [Accessibility]Press 'Tab' doesn't focus on the next report item when adding relative period aggregation.
xtab/org.eclipse.birt.report.item.crosstab.ui/src/org/eclipse/birt/report/item/crosstab/internal/ui/dialogs/CrosstabBindingDialogHelper.java
radioContainer.setLayout( layout );
		todayButton = new Button( radioContainer, SWT.RADIO );
		todayButton.addSelectionListener( new SelectionAdapter( ) {
			public void widgetSelected( SelectionEvent event )
			{
				dateButtonSelection( true );
			}
		} );
		todayButton.setText( Messages.getString( "CrosstabBindingDialogHelper.today.label" ) ); 
		todayButton.setLayoutData( new GridData( GridData.FILL,
				GridData.FILL,
				true,
				false,
				2,
				1 ) );
		dateSelectionButton = new Button( radioContainer, SWT.RADIO );
		dateSelectionButton.setText( Messages.getString( "CrosstabBindingDialogHelper.thisdate.label" ) ); 
		dateSelectionButton.addSelectionListener( new SelectionAdapter( ) {
			public void widgetSelected( SelectionEvent event )
			{
				dateButtonSelection( true );
			}
		} );
		Composite dateSelecionContainer = new Composite( radioContainer,
				SWT.NONE );
		GridData gridData = new GridData( GridData.FILL_HORIZONTAL );
		gridData.horizontalAlignment = SWT.FILL;
		gridData.grabExcessHorizontalSpace = true;
		dateSelecionContainer.setLayoutData( gridData );
		layout = new GridLayout( );