on delete cascade & hierarchical table

for MS SQL 2000
I am trying to do a hierarchical table and i want to add a ON DELETE CASCADE

CREATE TABLE [dbo].[Users](
[id_Users] [int] IDENTITY(1,1) NOT NULL PRIMARY KEY CLUSTERED,
[id_UsersSup] [int] NULL,
[Users] [nvarchar] (100) NOT NULL
) ON [PRIMARY]

ALTER TABLE [dbo].[Users] ADD
CONSTRAINT [FK_Users_Sup] FOREIGN KEY
(
[id_UsersSup]
) REFERENCES [Users] (
[id_Users]
)
ON DELETE CASCADE

but MS SQL refuse to create the foreign key
even if there is 4 levels under the deleted id_Users I want to delete all the rows on all levels under

thank you for helpingI tried running your code on SQL Server 2005, and got the following message:

Introducing FOREIGN KEY constraint 'FK_Users_Sup' on table 'Users' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints.

In my opinion, this error message tells pretty well why you are not allowed to use on delete cascade on a self-join.|||You will need to implement this cascading referential integrity using a trigger.