Changing Session Timeout Default 20 min

I'm trying to charge the default session timeout for the cart by creating a global.asa file and uploading it into our root directory (our cart is in a /shop/ sub-directory). This is the code that I'm trying to use:

<SCRIPT LANGUAGE="VBScript" RUNAT="Server">
Sub Session_OnStart
' Change Session Timeout to 20 minutes (if you need to)
Session.Timeout = 60
' Set a Session Start Time
' This is only important to assure we start a session
Session("Start") = Now
End Sub
</SCRIPT>

This doesn't seem to work though. I've read about 15 websites about how to do this and although they seem to do a lot of talking about it, I can't find a specific script that I can use/work. All I want to do is increase the default session timeout in the admin and cart from 20 minutes to 60 minutes. I find it frustrating to have to re-login to the admin and I'm sure the user would get very upset to shop, add mutlipe items, go eat a sandwich, come back and they're all  gone.

If the problem you seek to resolve is lost shopping sessions, you may find this useful: http://www.greybearddesign.com/productcart/session-saver/

I've not yet tried to install this on the admin but it may in fact be useful in that regard.  It will require modification for such an implementation.