Remove portal row when selected

[StooJ]

I'm sure there is a simple answer to this one, but can't figure it out.

I have three tables - a person table, an activity table & an activity occurrence. I made the activity occurrence table because I want to relate people to activities, but several people can be doing the same activity & and people can do one or many activities.

Using the activity occurrence table, I have a portal showing a list of all the people. Working my way through the activities I select each person involved with the activity via a portal.

The portal shows all the people via a cartesian (x) relationship.

First a new record is created in the activity occurrence table. The activityID field is populated automatically. Then, when I select a person, the personID field is populated.

Anyway, is there a way of removing a person once he or she is assigned to a particular activity? If I am filling in all the people taking part in activity 4, I don't want people already logged as being involved to show up in the portal.

Is there a way to do this via relationships?

Thanks all.

[Fenton]

This is called a "dwindling" value list. Here's an example file for FileMaker 8.5+ (uses the List() function).

Please update your Profile here.

Dwindle_List_portals.zip

[StooJ]

Absolutely perfect! Many thanks for the excellent example, Fenton.

Sorry about my profile, but I still seem to be mostly involved with FM6, even though for personal preference I'd rather join the 21st century!

I've changed it anyway, in hopes for the future.