restricting end users to insert data using a stored procedure

using a stored procedure, how can i restrict what a user INSERTS using a insert query, which could be restricted using WITH CHECK OPTION of a View?

like i want only steve and peter to insert data into a ITEM table. i have added a column 'USERS' in the ITEM table which consists of all the usernames. for this if i use view , then in the check option i give :

WHERE username='steve' OR username='开发者_开发技巧peter' WITH CHECK OPTION

but how do i do this using a stored procedure?

Something like this. You have to test for a user first and decide whether to allow. The test can be wrapped into another stored proc or UDF for re-use.

Question: how does your view know that Steve or Peter are the ones executing the view?

CREATE PROC myProc
   @p1 int
AS
SET NOCOUNT ON

BEGIN TRY
    IF SUSER_SNAME() NOT IN ('steve', 'peter')
       RAISERROR ('Oi: Steve and Peter only', 16, 1)

END TRY
BEGIN CATCH
   ...
END CATCH
GO

See my answer here for a stored proc template