I want to be able to link new entries to existing entries in different forms.

For example, in Form A have organisational contact details already entered (name, phone number, email address etc). Let's say Organisation 001 has 3 different people with whom I usually communicate.

And in Form B I am scheduling appointments.

If I schedule a new appointment in Form B for Organisation 001 whose details I've already entered in Form A, I want to then be able to specify which of the 3 different people it relates to. So I want a drop down list, or something, in Form B, that recognises that I've scheduled the appointment with Organisation 001, and therefore the dropdown list for the contact's name contains those 3 people only. And so on, so if I choose Person 1 from that drop down list, I will then be able to add Person 1's email address to the appointment, because that's what's listed in Form A.

Hope that makes sense? Can anyone help?

Thanks

David