Question : SQL creating table relationship trouble

I am developing a system where Users listed in the Users Table can select a set of Users from the same table as Trusted Friends, I store these selections in a seperate TrustedUser Table with an associated status message.

(* = primary key)

Users Table
--------------------------------------------
*UsersId         Name
1                Bob
2                Gill
3                Fred
4                Jim
(Auto-Increment)

TrustedUsers Table
--------------------------------------------
*UsersID  *TrustsUserID  Status
1         2              AwaitingVerification
1         3              Trusted
2         1              Trusted
2         4              Blocked

The way I understand it is I need to create UsersID & TrustsUserID as a combined primary key. and then create a relationship to UsersID (in the Users table)

I imagine the relationship should be

Users Table               TrustedUsers Table          
--------------------------------------------
UserID (1 to many)<-----> UsersID
UserID (1 to many)<-----> TrustsUserID  
           
But when I try to create the relationship in MS SQL 2002 I keep getting this error:

The columns in table 'Users' do not match an existing primary key or UNIQUE constraint.

I don't understand why as I have created the primary keys?

Can anyone spot what I'm doing wrong, im sure its something intensly trivial but my mind has gone blank, cheers.

Answer : SQL creating table relationship trouble

create table Users
(
UsersId int primary key ,
Name varchar(128) not null
)
go
create table TrustedUsers
(
UsersID int foreign key references Users (UsersId) ,
TrustedUsersId int foreign key references Users (UsersId) ,
primary key (UsersId, TrustedUsersId)
)
go