CREATE FUNCTION truncate_both(@str NVARCHAR, @left_n INT, @right_n INT )
                         RETURNS NVARCHAR
                         AS
                         BEGIN
                             declare @tempstr nvarchar(4000);
                             DECLARE @templen int;
                             
                             set @tempstr = SUBSTRING(@str, @left_n+1, LEN(@str));
                             
                             RETURN SUBSTRING(@tempstr, 1, LEN(@tempstr)-@right_n);
                         END;
GO