Bug 165624 Provides UI supports for Highlight rule refer to Style element
UI/org.eclipse.birt.report.designer.ui.views/src/org/eclipse/birt/report/designer/internal/ui/views/attributes/provider/HighlightDescriptorProvider.java
else if ( vv == 2 )
				{
					exp += " " 
							+ resolveNull( handle.getValue1( ) )
							+ " , " 
							+ resolveNull( handle.getValue2( ) );
				}
				return exp;
			default :
				return ""; 
		}
	}
	private String resolveNull( String src )
	{
		if ( src == null )
		{
			return ""; 
		}
		return src;
	}
	public boolean doSwapItem( int pos, int direction )
			throws PropertyValueException
	{
		PropertyHandle phandle = getDesignElementHandle( ).getPropertyHandle( StyleHandle.HIGHLIGHT_RULES_PROP );
		if ( direction < 0 )
		{
			phandle.moveItem( pos, pos - 1 );
		}
		else
		{