How to count unread messages

[Themusic]

Hi

I'm making a little message system with filemaker 15.

i have 4 tables:

- Users

- messages

- ricipients 

- join table to put together the above tables.

ricipient table is hold 22 records that are the 22 departements in my office.

In the join table there are those fields: id_ricipient_fk, id_message_fk, date and status.

the message table have a field that pick the sender account name

1 - what is the best method to set the "read" status in this table when the user open a message?

2 - how to count "unread" messages for every departements?

p.s. i use a multi data files structure and an interface file.

 

thanks a lot.

Claudio.

Edited February 1, 2017 by Themusic