function FillBilling(f) {
  if(f.shippingtoo.checked == true) {
    f.x_ship_to_first_name.value = f.x_First_Name.value;
    f.x_ship_to_last_name.value = f.x_Last_Name.value;
    f.x_ship_to_address.value = f.x_Address.value;
    f.x_ship_to_city.value = f.x_City.value;
    f.x_ship_to_state.value = f.x_State_US.value;
    f.x_ship_to_state_other.value = f.x_State_Other.value;
    f.x_ship_to_country.value = f.x_Country.value;
    f.x_ship_to_zip.value = f.x_Zip.value;
    /* If more fields are used, just expand the parameters
       above to include the additional fields. */
  }
}