knack database jquery or javascript creation / editing

I use Knack databases, an online service: [login to view URL] With Knack, I have an app that needs either a script, or a jquery, or a javascript. I don't speak these languages, but I generally know what I need and want. I have attached a sample code snippet that Knack provided in their example app "Attendance." It should provide insight and a template on how to do what I want. When users click on "Submit" button in the "Add Class Day" under "Classes > View Star Class Day Details > Add Class day" form, I want all swimmers connected to that class to have a "Class Attendance" record inserted that is connected to that Class day with a "NO" in the "At Class" field. When a class day is created, I want every member of that class to have a class attendance record created with the "at class" field value set to "no." There are three different pages where this similar script is needed, but tailored to the exact button and form.