Please tell us more about your database.
What tables have you defined?
How are they related?
In particular, how id you set up this portal in terms of relationship and portal set up options?
I would assume that "date" in your screen shot records the date a review copy was sent out to a recipient?
Do you know how to create fileMaker Scripts?
Thanks so much for responding! No, unforuatenly I don't have any experience with FileMaker Scripts. I'm moving our company's publicity database over from *gasp* Approach 96'.
The database lists contact information (Name, Email, Mailing address) and is based off of the Contact Managment Starter Solution. I'm trying to add a section where I'll be able to track the number and type of review copies sent, the date they were sent, and followup dates. The following tables have been definied: Contact Management, Review Copies, and Notes. You'll have to forgive me lack of FMP knowledge, but as far as I can see the Review Copies table is related to the Contact Management table by the Client ID (Client ID=Client ID).
Better check the field options for Review Copies::clientID. I don't see the needed "crows feet" that indicate that this is a "one to many" relationship between a contact and potentially many review copies records. This field should be the same data type as Contact Management::clientID and should not be set up to enforce unique values nor should it be defined as an auto-entered serial number here.
If I understand what you want, If you send out a book titled "Xyz" on Sept 9, 2011, you want to mark all such records with the same followup date?
A script can do this, but you need to know how to create and run scripts for this to work for you.
A button placed next to the Followup1 field inside the portal can run the following script:
Set Variable [$Book ; Value: Review Copies::Book ]
Set Variable [$DateSent ; Value : Review Copies::DateSent ]
Set Variable [$FollowUpDate ; Value : Review Copies::Followup1 ]
go To layout [Review copies]
Enter find mode  // clear the pause check box
Set Field [Review Copies::Book ; $Book]
Set Field [Review Copies::DateSent ]
Set Error capture [on]
Perform Find 
Replace Field Contents [no dialog ; Review Copies::Followup1 ; $FollowUpDate ]
Go To Layout [original layout]
An alternative option that does not require a script, is to place a global date field on your layout and enter a follow up date into it. Then the Followup1 field can use a field option to auto-enter the date in this field each time a new record in Review Copies is created.