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
}
		return ""; 
	}
	private void initTextField( Text txtParam, IParameterDefn param )
	{
		if ( paramsValueMap.containsKey( param.getName( ) ) )
		{
			txtParam.setText( paramsValueMap.get( param.getName( ) ) );
			return;
		}
		if ( binding != null )
		{
			for ( Iterator iterator = binding.argumentsIterator( ); iterator.hasNext( ); )
			{
				AggregationArgumentHandle arg = (AggregationArgumentHandle) iterator.next( );
				if ( arg.getName( ).equals( param.getName( ) ) )
				{
					if ( arg.getValue( ) != null )
						txtParam.setText( arg.getValue( ) );
					return;
				}
			}
		}
	}
	/**
	 * fill the cmbDataField with binding holder's bindings
	 * 
	 * @param param
	 */
	private void initDataFields( Combo cmbDataField, IParameterDefn param )