HOW To Create An SQL User Using Parameters ?

Hello !

I want to create DB users with an stored procedure, and pass the user name as a parameter.
I wrote this code :

CREATE PROCEDURE [dbo].[spTest]

(


@ComName varchar(20),

)

AS

BEGIN


SET NOCOUNT OFF;

CREATE USER [@ComName] WITHOUT LOGIN WITH DEFAULT_SCHEMA = dbo;

END


If I execute this stored procedure :


DECLARE @return_value int

EXEC @return_value = [dbo].[spTest]

@ComName = N'Test_User',

SELECT 'Return Value' = @return_value

I obtain in my DB an user called "@ComNane" instead of "Test_User" !
Where is my mystake ?

Many thanks for any help.

Luc