Comma Separated Columns List With Table In Sql Server

DECLARE @LIST VARCHAR(8000) 

SELECT @LIST = COALESCE(@LIST + ', ', '') 
               + Cast(COL.NAME AS VARCHAR) 
FROM   SYS.OBJECTS OBJ 
       LEFT JOIN SYS.COLUMNS COL 
              ON COL.OBJECT_ID = OBJ.OBJECT_ID 
WHERE  OBJ.NAME = 'TABLENAME' 
ORDER  BY COLUMN_ID