'onchange' events to Product Attributes Menu

Some questions about product attribute menus:

How do we add custom "onchange" events to product attribute menus? onchange events are individual for each attribute and we have XX number of attributes.

Also, once we have our own onchange events added to the menus, do we just add our own javascript to handle them by adding it to our custom template page?

Finally, how can we customize the default exported drop down menus from ZenCart, (e.g. remove their labels, add css classes to the drop downs, etc)?

Thank you!!!

You're asking some very complex questions which can't really be answered here in the general forums.

I suggest you post in the Commercial Help Wanted forum.

Thank you!