地図のMarkerをクリックで、場所の名前を表示する機能

function create_marker(lat, lng, name) {
  var marker_options = {
    map: map_canvas,
    position: new google.maps.LatLng(lat, lng),
    zIndex: 0
  };

  var marker = new google.maps.Marker(marker_options);
  var infowindow = new google.maps.InfoWindow({
    content: name
  });

  marker.addListener("click", function() {
    infowindow.open(map_canvas, marker);
  });
}