Force Logout

It seems that if one of my members does not log out, that they will stay logged in indefinitely.

Is there a way to force a logout using a timer or at least force a logout when they close the browser window?

For example, when I am in my aMember CP if I remain inactive for a certain amount of time I am automatically logged out. I would like to duplicate this method for my members.

Thanks

No, Remember Login and Always remember are both set to No.
Is there a timer in the code?

Yes, wordpress and amthankyou. Is there a place in the code I can set a timer like the one in my aMember CP?

Is there a way to force a logout by clicking a logout button?

Got it, all set here.