Business Tracker - Auto. updating inventory

[bizou]

I am trying to customize Business Tracker and need to add a script to automatically update the inventory of an item when an item are sold. I noted that BT does not have this built into. Has anyone created such a script or have any advice on doing so? I saw a similar thread re FMP 6, but would like specific info on BT in FMP 7 if available.

TIA