Access Database Evaluation

Hi

I'm trying to create a database for an organization for managing contact lists, and mettings with access 2007.

I've 4 tables, organization, person, meeting, participant (contains fields of person and meeting).

the PK for person is, "Fname" and "Lname", and the PK for meeting is "name of meeting" and "date of meeting".
How should I link these two tables with "participant" which has no PK, in order to avoid people to insert fields for partcipand before filling out data tables of person and meeting.

Thanks in advance

Ali