I have a form containing a multi-select check box field that is dynamically populated from a look-up table according to a field selected above it. Eg. "Training Type" dynamically populates "Training Subjects" according to the Training Type selected.

QUESTION: How do you configure  the "On Edit" to populate the Edit form properly and allow you to submit the updates?

I assume the multi-select field needs to be populated from the "On Update / On Load" function, but I can't figure it out. Either I get all subjects from the look-up table, or the ones that I need only for the subject, but the check boxes are cleared of the previous selections. When I try to submit an update/edit, it throws a bunch of errors.