Filtering subform data

[Lisa Reber]

Have been working on this on and off since February. Have
the following tables:
Contacts
Vehicles
ContactVehicles
Am working on a fourth table, VehicleRegis.

Have the following form / subform working
Contacts
ContactVehicles link parent/child on ContactID

I'm stumped in trying to add another subform for
registration details.
Want to enter date / amount paid and then select vehicle
(s) from the
subform ContactVehicles, rather than tblContactVehicles.

I have the following advice from an earlier post: "For the
details subform, I would not link parent/child fields;
instead, I would filter it by the VehicleID from the
vehicles subform in the vehicles subform current event."
This just isn't getting through to me.

Any help is appreciated - thanks in advance. - Lisa