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
binding.setDataType( DATA_TYPE_CHOICES[i].getName( ) );
					break;
				}
			}
			binding.setDisplayName( txtDisplayName.getText( ) );
			binding.setDisplayNameID( txtDisplayNameID.getText( ) );
			if ( ExpressionButtonUtil.getExpressionButton( txtExpression ) != null )
			{
				ExpressionButtonUtil.saveExpressionButtonControl( txtExpression,
						binding,
						ComputedColumn.EXPRESSION_MEMBER );
			}
			else
			{
				Expression expression = new Expression( getControlValue( txtExpression ),
						ExpressionType.JAVASCRIPT );
				binding.setExpressionProperty( AggregationArgument.VALUE_MEMBER,
						expression );
			}
		}
		if ( isTimePeriod( ) )
		{
			ITimeFunction timeFunction = getTimeFunctionByIndex( calculationType.getSelectionIndex( ) );
			String dimensionName = timeDimension.getText( );