EDIT procedure for fields in cluster?

[roger32909 at bellsouth.net]

PH 7.10G on OpenVMS.
We have a screen with a cluster of some nine fields arrayed horizontally, e.g.

	Field1	Field2	Field3, etc.
09
10
11
12

We are trying to prevent entries of zero for date and quantity fields.
However, it appears that an EDIT procedure only works for Field1.  EDIT procedures for subsequent fields appear to have no effect for one can easily enter zero and continue.  Of course, we can test for this in a PREUPDATE  procedure, but we would like to give immediate feedback to the user.  Is there something special that needs to be coded in EDIT procedures for fields in a cluster without their own ID?