CONFMAN.registration_setup_paypal_wpp = function() {

  var update_cc_options = function(region) {
    var box = $('discover_option');
    if (region === 'US') {
      box.appear({duration: 0.5});
    } else {
      box.fade({duration: 0.5});
      box.checked = false;
    }
    return this;
  };

  $$('input[name=payment_wpp_region]').invoke('observe', 'change', function(e) {
    var region = Event.findElement(e, 'input[type=radio]').value; 
    update_cc_options(region);
  });

};