Dynamically setting the timeout?

Hi all,
I have a website which as far as I know has the following timeout settings:
1) In Web.config, FORM's authentication timeout="10"
2) In Web.config, MEMBERSHIP's userIsOnlineTimeWindow="10"
3) Assigned in Global.asax on Session_Start(): Session.Timeout =10;


In the past I had problems because at least 1) and 3) weren't in sync, not sure about 2).
Do these 3 have to be in sync and if so, is there a way to set the timeout once and to have it applied to all 3? I deploy my website to many clients and each may want a different timeout, so I'm looking for a dynamic method to set this, perhaps after loading the timeout period from the db or settings file.


Any idea?


Many thanks

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