create procedure sys.sp_MSdrop_qreader_agent
(
    @agent_id int = NULL
) AS
BEGIN
    SET NOCOUNT ON
    
    -- Declarations.
    
    DECLARE @retcode        int
    DECLARE @job_id         binary(16)
    DECLARE @job_step_uid	uniqueidentifier
    DECLARE @name           nvarchar(100)
    DECLARE @database       sysname

    select @database = db_name()

	IF @agent_id is NULL
	BEGIN
		SELECT TOP 1 @agent_id = id
			FROM MSqreader_agents
	END

    -- get the agent and job ids
    SELECT @job_id = job_id, @name = name, @job_step_uid = job_step_uid
    FROM MSqreader_agents
    WHERE id = @agent_id

    if (@agent_id is NULL)
        return (0)

    -- Delete Perfmon instance
    dbcc deleteinstance ('SQL Replication QueueReader', @name)

    BEGIN TRAN sp_MSdrop_qreader_agent

    -- delete job for the agent
    IF EXISTS (SELECT * FROM msdb.dbo.sysjobs_view WHERE job_id = @job_id)
    BEGIN
        -- Checks if the job name was generated
        EXEC @retcode = sys.sp_MSisqueuereaderjobnamegenerated
                            @job_id = @job_id

        IF @@ERROR != 0
            GOTO UNDO

        -- Only drop the job if the name was generated
        IF @retcode = 0
        BEGIN
            EXEC @retcode = sys.sp_MSdrop_repl_job @job_id = @job_id,
            										@job_step_uid =  @job_step_uid
            IF (@@ERROR != 0 or @retcode != 0)
                GOTO UNDO
        END
    END

    -- Remove agent entry
    DELETE MSqreader_agents WHERE id = @agent_id
    IF (@@ERROR != 0)
        GOTO UNDO

    -- Remove associated history
    DELETE MSqreader_history
    WHERE agent_id = @agent_id
    IF (@@ERROR != 0)
        GOTO UNDO

    COMMIT TRAN sp_MSdrop_qreader_agent
    RETURN(0)

UNDO:
    ROLLBACK TRAN sp_MSdrop_qreader_agent
    return(1)
END