Dependent dropdowns

hi,
it is possible to recreate this example for dependent
drop-downs(http://www.dse.se/pulsar/AjaxDemo/AjaxDemo.html?countryId_old=119®...)

i have 4 tables : country, region, city and customer with dependent
foreign key. id_loc.customer
->id_loc.city->id_loc.region->id_loc.country
i have only generated 4 scaffold for the tables.
thanks