SQL Incorrect syntax near

DECLARE @objname varchar(150), @type varchar(10), @usr varchar(20), @sql nvarchar(100);
SET @usr = "tempdwlogin';
 
DECLARE read_only_cur CURSOR FOR 
SELECT sc.name + '.' + ob.name, ob.type
FROM sys.objects ob, sys.schemas sc
WHERE ob.schema_id = sc.schema_id
AND ob.type IN ('U', 'V', 'FN', 'IF', 'TF', 'FS', 'FT','P', 'PC');
 
OPEN read_only_cur;
FETCH NEXT FROM read_only_cur
INTO @objname, @type;
WHILE @@FETCH_STATUS = 0
   BEGIN
   	  IF @type IN ( 'U', 'V')
   	  BEGIN
   	  	SET @sql = N'GRANT SELECT ON ' + @objname + N'TO ' + @usr;
   	  	EXEC sp_executesql @sql;
   	  END
   	  ELSE
   	  	BEGIN
   	  	   SET @sql = N'GRANT EXECUTE ON ' + @objname + N'TO ' + @usr;
   	  	   EXEC sp_executesql @sql;
   	  	END
      FETCH NEXT FROM read_only_cur;
   END;
CLOSE read_only_cur;
DEALLOCATE read_only_cur;