Who block Who?

SELECT  D.name ,
        R.Session_ID ,
        S.login_name ,
        S.nt_user_name ,
        R.Start_time ,
        R.STATUS ,
        R.Command ,
        R.blocking_session_id ,
        SB.login_name blocking_login_name ,
        T.text
FROM    sys.dm_exec_requests R
        CROSS APPLY sys.dm_exec_sql_text(R.sql_handle) T
        INNER JOIN sys.DATABASES D ON R.database_id = D.database_id
        INNER JOIN sys.dm_exec_sessions S ON R.session_id = S.session_id
        LEFT JOIN sys.dm_exec_sessions SB ON R.blocking_session_id = SB.session_id
WHERE   R.sql_handle IS NOT NULL