Trigger Cascade Update

i run this cmd to execute a cascade update to another database but did not work.

USE [testdb1]
GO
/****** Object: Trigger [dbo].[tgr_Upddb2] Script Date: 07/29/2007 08:34:47 ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO
ALTER TRIGGER [dbo].[tgr_Upddb2]
ON [dbo].[Table1]
FOR UPDATE
AS
BEGIN
SET NOCOUNT ON

UPDATE U
SET u.fk_fld = i.pk_fld
FROM inserted AS I
JOIN testdb2.dbo.table2 AS U
ON U.fk_fld = I.pk_fld
END


heres the db structure