Transactions through JDBC

Hi all!

Actually I have a client-server application with one server and many
clients each one of which opens a different connection to the postgres
database. In order to avoid those known problems with the execution of
the different clients' operations at database, I implemented
everything in this way. Each operation is made so:

conn.executeUpdate("BEGIN");
conn.execute(...)
conn.execute(...)
conn.execute(...)
conn.executeUpdate("COMMIT");

May it be considered right, or am I making something wrong? I use JDBC
driver for postgres 8.1

Thanks!