What you describe should be possible if clicking a check box performs a script to add records in the portal. There's more than one way to do that and the precise details can depend on your database design.
Thanks fpr the reply Phil.
I have set up scripts that do add records to the portal already, but the problem is that more than one checkbox can add the same Crew type which i do not want. Also, the checkboxes are not the only thing that can add crew to the portal. There is also a radio button selection amungs other things.
Here is a screenshot of what the layout looks like
Your script that adds records can check for the existance of a specific record and not add it if it is already present.
IsEmpty ( Filtervalues ( List ( Portaltable::Field ) ; "ValueToAddHere" ) )
will be true, if "ValueToAddHere" is not already the value in PortalTable::Field for one of the records in your portal.
That works perfectly!
Thank you so very much PhilModJunk! You are a superstar!