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
{
							
							Combo combo = (Combo) control;
							String str = obj.getStringExpression( );
							if ( str == null || str.length( ) == 0 )
							{
								combo.select( 0 );
							}
							else
							{
								int comboIndex = getItemIndex( combo.getItems( ),
										str );
								if ( comboIndex >= 0 )
								{
									combo.select( comboIndex );
								}
								else
								{
									combo.select( 0 );
								}
							}
						}
						
						if ( control instanceof Text && argValue != null )
						{
							( (Text) control ).setText( argValue );
						}
					}
				}
			}