document.addEventListener("DOMContentLoaded", () => {
  var gsi = L.tileLayer('//cyberjapandata.gsi.go.jp/xyz/std/{z}/{x}/{y}.png', {
    attribution: '&copy; <a href="https://maps.gsi.go.jp">国土地理院地図</a> contributors'
    });
  var osm = L.tileLayer('//{s}.tile.openstreetmap.org/{z}/{x}/{y}.png', {
     attribution: '&copy; <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'
    });

  var gpsmap = L.map("seek", {zoomControl: false });
  gsi.addTo(gpsmap);
  gpsmap.setView([38.8675, 139.8190], 12);

  var baseMaps = {
    "地理院地図" : gsi,
    "OpenStreetMap" : osm
  };

  L.control.layers(baseMaps).addTo(gpsmap);
  L.control.zoom({ position: 'topleft' }).addTo(gpsmap);
  L.control.scale({ position: 'bottomright' }).addTo(gpsmap);

  console.log('error');
}, false);