We have a business requirement for our project site. On a task, there is a multi-select people picker field that people put "Interested Parties" in. These people get certain email updates and such. It has now been requested that we generate an email to any person who is added after the creation to this field. The only solution I can think of for this is to have a field called "Add to Interested Parties," have an email generated to that person (or those people) then append those people to the "Interested Parties" field and wipe out the "Add To" field.
I tried having a second hidden interestedParties2 field so I could check for a diff. But once I saw the diff, I was having trouble determining which was the "new entry" so that I could generate the email (the requirement is to send the email only to the newly added person).