Preserving data in related file when master is changed

[Peter Knowles]

I have a master database with names of 450+ students, used for them to log in and out of an afterschool program each day using CDML/Web page submit buttons. I've created a FMP script which allows the administrator to reset all students to "logged out" status at the end of each day (in case some of the students have forgotten) so the next day, all students need to log in. However, I also need to preserve a lasting record of which students logged in each day, and I'm not sure how best to approach this.

I created a database with fields related to the master (students' numbers, date of log in, time of login and logout), and a calculation field which calculates elapsed time for each student.

Now the question is, how do I fill those related fields with lasting data from the master -- which will be reset at the end of the day. Right now, when I edit the records in the master (logging students in and out, generating checkin dates and times) no changes occur in my related file. (I admit, this is my first and long-delayed foray into the world of relationships, so I may be missing a very simple point as to why it doesn't work.)

I think the solution to my problem lies in how I set up the relationship, so I hope I've got the right forum. (though it could be a scripting solution or maybe even field definition, maybe CDML?) so please forgive me if I've placed this plea in the wrong forum. I realize there are probably lots of ways to go about this. I'd settle for even one.