Dynamically populate drop downs that are part of form array

[mickyjune26]

Thanks to this great forum, I have created the form below that allows me to duplicate rows of form data using the cloneNode function.  The form data is passed to a form array that I modified using PHP.

 

I have also figured out how to populate a 2nd drop-down based on the selection of the first.

 

I'm having trouble combining these two concepts.

 

http://www.einstructiontx.com/content_promo_form.html

 

I would like to keep all existing functions on the form..and add the ability to populate Subject based on Grade Level.  In other words, I don't want "Marketing" to appear when someone selects 1st Grade!