Hi Paul

I'd use THISFORM.ShellBeforeUpdateBuffers() to

1 - requery my "in stock" view to obtain a list of the current availability of the widgets on the current invoice

2 - update those records as you suggested

3 - let VMP proceed with THISFORM.UpdateBuffers().

If the updates fail, its because someone sold one or more widgets while your update was running. That shouldn't occur too frequently. If there is an update conflict during this brief period, warn the user and let them click save again.

HTH

Mike