mysql中存储过程与事务

例如下：
create procedure trade()
begin
     update account set balance = balance - 100 where uid = 1;
     update account set balance = balance + 100 where uid = 2;
end//

怎么样用事务保证俩SQL语句都执行呢？
期待，高手解决......

有没有人会呀？
急呀，版主在不在呀？？？？？？？