getting responseID of latest form submission in google apps

Question

I have a google form. Every time it is submitted, the answers go into a google spreadsheet. I am trying to write an app script that triggers every time the form is submitted

Answer 1

The solution is to remove:

var form = FormApp.getActiveForm(); //this is WRONG

and replace with:

var form = FormApp.openByID(' ID here ')

There is no "active form", because this script is being run in sheets, not forms.