Dependant comboboxes ... can anyone help?

We’ve all been to driver download pages where you select your model from one combobox list and then that choice populates the next combobox of choices and then that combobox choice spawns a link to the driver.

I’m trying to figure out how to do that in flash.

Combobox 1 will display a list of 14 items. Each item in that list has a subset of 3-4 items that will appear in combobox 2 once a selection is made. Then when a selection is made in combobox 2 a link will appear for a download

does anyone know how to do this?