MYSQL out parameter

Iḿ very new to sql; I wrote the following stored procedure but I do not receive the out parameter with the correct result (allways null).
……………….
CREATE DEFINER=`myDB`@`localhost` PROCEDURE `testSP`(in _SN varchar(20), in _ProdLine int, out Result tinyint)
BEGIN
Declare exit handler for sqlexception select Result = 1;

insert into testTB (DateTime, SN, ProdLine) values (Current_Timestamp(), _SN, _ProdLine);
select Result = 0;
END
…………..
Which error am I doing ?…

MYSQL out parameter