commit from powerbuilder to infromix 7.2

Hello, reading powerbuilder 4 help, I find that autocommit is not supported for = Informix databases, i.e., it is always set to false. If you use exclusively stored procedures in an application, i.e, no = select in clients, which is the " right" way to deal with transactions = and stored procedures then, from powerbuilder: a) control transactions entirely in the pb-client, no begin work, commit = or rollback issued inside stored procedures? b) control entirely in procedures, no commit or rollback in = powerbuilder? what happens then with the initially open transaction = (connect)? c) both can be used? Another question: what happens to the open transaction if while = executing a stroed procedure the client crashes? is it automatically = rolled back or (I hope not!) commited?