function ChangeTown(chooser, form_name, fld, selec) {
    var newElem;
    var where = (navigator.appName == "Microsoft Internet Explorer") ? -1 : null;
    eval("cityChooser = document."+form_name+"."+fld);
    while (cityChooser.options.length) {
        cityChooser.remove(0);
    }
    var choice = chooser.options[chooser.selectedIndex].value;
    var db = regiondb[choice];
    if (choice != "0") {
        for (var i = 0; i < db.length; i++) {
            newElem = document.createElement("option");
            newElem.text = db[i].text;
            newElem.value = db[i].value;
            if (db[i].value == selec) {
                var needsel = i;
            }
            cityChooser.add(newElem, where);
        }
    }

    cityChooser.selectedIndex = needsel;
}