OK, I've tried searching old posts for the answer to my question, and I have now ruined my eyesight. I'm going to try a new post. This should be a cinch - but it's making me crazy. I have a donor database in which I want to enter new donations and have each donation be a separate record in a related database, attached to a unique serial number for each donor. I had it working for a bit - but each record in the donations database was being assigned a new serial number instead of the actual donor's serial number. In an attempt to fix it, I am now getting a message when I try to enter anything into one of the donation fields in the portal "This field cannot be modified until <<field name>> is given a valid value". I know this can be done. I am sitting here looking at an older database that basically does what I want done, but I can't see how the designer did it. And I don't want to just use that database, I want to know how it's done! Please help me before I go completely over the deep end!

>>... attached to a unique serial number for each donor.

http://www.nightwing.com.au/FileMaker/demos/CustomSerial.sit

>>I am now getting a message when I try to enter anything into one of the donation fields in the portal "This field cannot be modified until <<field name>> is given a valid value".

Check the relationship - it seems got broken