I need to create different registration forms for different classes,

after I type in the name, I hope that the database will search for the

participant information and fill in the information in the registration

form automatically.

I wonder how to define the relationships for this. Thanks a lot.

It's generally not a good idea to base your relationships on names, or anything that is actual "data." A better approach is to auto-enter an I.D. for each person, i.e. a serial number that is only used for relationships and doesn't change, even if the person changes their name or something.

Once you have that, it's a simple matter to enter the person's ID in the "classes" db, and have it look up info from the "participant" db. Another method would be to not lookup, but rather maintain a link between the classes and participant files with a 3rd file which would store in each record a participant id and a class id. This is called a join file and is necessary for a many-to-many relationship. I suggest these articles:

http://www.FileMaker.com/ti/103734.html

http://www.FileMaker.com/ti/102582.html