> I'm new to using databse thru Java and I don't have learned knowledge
> in this(my co-worker just gave me a few layout his boss made and told
> me to follow it), so I don't know much about these erros (and my
> co-worker says he doesn't know too).

It seems that you do not return your connection back to the pool. In Java
normally this happens by simply closing the connection. This works, since
you work not with a real connection, but with a proxy and Connection.close()
method just marks the underlying physical connection as free.

It is hard to give you any concrete advice, since there are many different
ways how connection/statements are used. The only generic rule is - return
connection back to the pool as soon as you finished working with it in the
particular case. Cost of obtaining connection from the pool is very small
(and even cost of opening new connection to Firebird is not high).

Roman