function updateRegion( country, region) {

  try {
    while( region.length > 1)
      region.remove( region.length - 1);

    countryCode = country.options[ country.selectedIndex].value;
    if( countryCode != "N/A") {
      var countryRegions = regions[ countryCode];
      var option = document.createElement("option")
      option.appendChild(document.createTextNode("dummy"));
      for( var i in countryRegions) {
        option.value = i;
        option.replaceChild(document.createTextNode(countryRegions[ i]), option.firstChild);
        region.appendChild(option.cloneNode(true));
      }
      region.disabled = false;
    }
  } catch( e) {
    region.disabled = true;
  }
}

function updateCity( region, city) {

  try {
    while( city.length > 1)
      city.remove( city.length - 1);

    regionCode = region.options[ region.selectedIndex].value;
    if( regionCode != "N/A") {
      var regionCities = cities[ regionCode];
      var option = document.createElement("option");
      option.appendChild(document.createTextNode("dummy"));
      for( var i in regionCities) {
        option.value = i;
        option.replaceChild(document.createTextNode(regionCities[ i]), option.firstChild);
        city.appendChild(option.cloneNode(true));
      }
      city.disabled = false;
    }
  } catch( e) {
    city.disabled = true;
  }
}

function updateRegionsNCities( country, regionCity) {

  try {
    while( regionCity.length > 1)
      regionCity.remove( regionCity.length - 1);

    countryCode = country.options[ country.selectedIndex].value;
    if( countryCode != "N/A") {
      var countryRegions = regions[ countryCode];
      var option = document.createElement("option")
      option.appendChild( document.createTextNode("dummy"));
      for( var i in countryRegions) {
        option.value = i + "00000";
        option.replaceChild( document.createTextNode( countryRegions[ i]), option.firstChild);
        regionCity.appendChild( option.cloneNode(true));

        var regionCities = cities[ i];
        for( var j in regionCities) {
          option.value = i + j;
          option.replaceChild( document.createTextNode( "     " + regionCities[ j]), option.firstChild);
          regionCity.appendChild( option.cloneNode(true));
        }
      }
      regionCity.disabled = false;
    }
  } catch( e) {
    regionCity.disabled = true;
  }
}