This document discusses how to automatically kill idle sessions in NAVThreeTier. It explains that NAV 2009 and later versions have a "ClientReconnectPeriod" or "IdleClientTimeout" parameter that can be used to achieve this without any coding. It provides steps to set this parameter by opening the service tier, editing the desired service, going to the ClientServices tab, inputting the time delay in "IdleClientTimeout" in a specified format, saving and restarting the service. It demonstrates that idle sessions will then be removed after the set time and users will get an error if trying to access.