jQuery(function($) {

  var $gmaps = google.maps, map;

  var panTo = function(lat, lng) {
    map.panTo(new $gmaps.LatLng(lat, lng));
  };

  var errMes = function(e) {
    $('input#latlng').val('Not Found!');
  };

  $('input#btn').click(function() {
    geocode($('input#address').val(), panTo, errMes);
  });

  var mapload = function(lat, lng) {
    map = roadmap('mapArea', lat, lng, 16);
    var marker = map.addMarker(lat, lng);
    map.bindTo('center', marker, 'position');
    map.addListener('center_changed', function() {
      $('input#latlng').val(this.getCenter().toUrlValue());
    });
  };

  $gmaps.event.addDomListener(window, 'load', function() {
    mapload(22.322764, 114.170688);
  });

});