diff --git a/public/index.js b/public/index.js
index bd63558..f6b5a74 100644
--- a/public/index.js
+++ b/public/index.js
@@ -1,6 +1,21 @@
+'use strict'
+
 let map = L.map('map');
 map.setMaxBounds(L.latLngBounds(L.latLng(33.9033300, 134.2141300), L.latLng(34.08, 134.4836400)));
-map.setView([33.96515, 134.34889], 13);
+
+let default_marker = null;
+(() => {
+	map.setView([33.96515, 134.34889], 13);
+	const params = new URLSearchParams(document.location.search);
+	let lat = params.get('lat');
+	let lon = params.get('lon');
+	if(lat !== null && lon != null)
+	{
+		map.setView([lat, lon], 16);
+		default_marker = L.marker([lat, lon]);
+		default_marker.addTo(map);
+	}
+})();
 
 //L.tileLayer('https://tile.openstreetmap.org/{z}/{x}/{y}.png', {
 L.tileLayer('/{z}/{x}/{y}.png', {
@@ -15,7 +30,9 @@ let popup = L.popup();
 function onMapClick(event) {
 	popup
 		.setLatLng(event.latlng)
-		.setContent(`GPS: ${[event.latlng.lat, event.latlng.lng]}`)
+		.setContent(`<div>Latitude: ${event.latlng.lat}</div>
+			<div>Longitude: ${event.latlng.lng}</div>
+			<div><a href='/?lat=${event.latlng.lat}&lon=${event.latlng.lng}'>link</a></div>`)
 		.openOn(map);
 }
 map.on('click', onMapClick);