Idle connections - Too many clients connected already

Hello,

After using Postgresql for a while, through ODBC / MS Access, I'm not
able to connect to the server anymore. The server reports "Too many
clients connected already".

With a "ps -afx", I can see a lot of idle postgresql connections, which
correspond for sure to ODBC connections that haven't been closed
properly, and that remain opened. Stopping and restarting the server
solves the problem.

Is there a way to avoid that? I cannot certifiy that clients will always
close their connexions in a clean way. So, is the server able to check
if clients are still alive, and close their connexion if it's not the
case? I never had anything like that with MS SQL Server...

Thanks

Philippe