subscription small modification needed

[indie]

This seems like it should be simple, but I do not know PHP so need some help.

I use paid subscriptions with primary usergroup changes. The problem I have (and others, since this is a fault) is, members "upgrade", so when the newest subscription expires, it does not send them back to registered users.

Example:

Say I have gold and platinum primary usergroup subscriptions. Say someone gets gold for one year. Then, a month later, they get the platinum for one year. Now, when the platinum expires, it sends them back to gold, instead of registered users, because they went to platinum "from" gold. It does this even though gold has been expired, because it sends to previous usergroup.

So, what I need to do, is in the code, have all expired subscriptions go to the registered users group, instead of the "upgraded from" usergroup (unless someone has a better solution).

I still need it to check for other subscriptions, which it currently does, so that should not change. For example, when the gold expires (the first subscription to expire if a member has upgraded to platinum) it will not remove then from platinum when gold expires because they are in a different usergroup. The way it is now vbulletin already does this correctly, and I want to make sure it still does this.

Thanks if anyone can help!