diff --git a/index.html b/index.html
index 061103e..149a183 100644
--- a/index.html
+++ b/index.html
@@ -68,6 +68,7 @@
     mapboxgl.accessToken = 'pk.eyJ1IjoiamVubnlmcm9tdGhhYmxvY2siLCJhIjoiY2x5dWQwa3dwMTI1aTJscHVtOHR1ZmUxdyJ9.NZSYIPeI4A96tF6sWSIRvQ';
 
     let startPoint = [];
+    let destinationPoint = [];
     let map;
     let directions;
 
@@ -103,81 +104,111 @@
 
       console.log(`Starting Point: ${startPoint}, Distance: ${distance} meters, Round Trip: ${roundTrip}, Hills: ${hills}, Stores: ${stores}`);
 
-      map = new mapboxgl.Map({
-        container: 'map',
-        style: 'mapbox://styles/mapbox/outdoors-v11',
-        center: startPoint,
-        zoom: 14
-      });
-
-      map.on('load', async () => {
-        map.addLayer({
-          'id': 'hillshading',
-          'source': {
-            'type': 'raster-dem',
-            'url': 'mapbox://mapbox.terrain-rgb'
-          },
-          'type': 'hillshade'
+      if (!map) {
+        map = new mapboxgl.Map({
+          container: 'map',
+          style: 'mapbox://styles/mapbox/outdoors-v11',
+          center: startPoint,
+          zoom: 14
         });
 
-        new mapboxgl.Marker()
-          .setLngLat(startPoint)
-          .addTo(map);
-
-        directions = new MapboxDirections({
-          accessToken: mapboxgl.accessToken,
-          unit: 'metric',
-          profile: 'mapbox/walking'
-        });
-
-        map.addControl(directions, 'top-left');
-
-        let routeFound = false;
-        let attempts = 0;
-        const maxAttempts = 10;
-
-        while (!routeFound && attempts < maxAttempts) {
-          const angle = Math.random() * Math.PI * 2;
-          const dx = Math.cos(angle) * (roundTrip ? distance / 2 : distance);
-          const dy = Math.sin(angle) * (roundTrip ? distance / 2 : distance);
-          const waypoint = [startPoint[0] + dx / (111320 * Math.cos(startPoint[1] * Math.PI / 180)), startPoint[1] + dy / 110540];
-
-          directions.setOrigin(startPoint);
-          directions.setDestination(roundTrip ? startPoint : waypoint);
-
-          const route = await new Promise((resolve) => {
-            directions.on('route', (e) => {
-              resolve(e.route[0]);
-            });
+        map.on('load', () => {
+          map.addLayer({
+            'id': 'hillshading',
+            'source': {
+              'type': 'raster-dem',
+              'url': 'mapbox://mapbox.terrain-rgb'
+            },
+            'type': 'hillshade'
           });
 
-          if (route.distance >= distance * 0.8 && route.distance <= distance * 1.2) {
-            routeFound = true;
-            if (hills) {
-              map.setLayoutProperty('hillshading', 'visibility', 'visible');
-            } else {
-              map.setLayoutProperty('hillshading', 'visibility', 'none');
-            }
-            console.log(`Route distance: ${route.distance} meters`);
+          new mapboxgl.Marker()
+            .setLngLat(startPoint)
+            .addTo(map);
+
+          directions = new MapboxDirections({
+            accessToken: mapboxgl.accessToken,
+            unit: 'metric',
+            profile: 'mapbox/walking'
+          });
+
+          map.addControl(directions, 'top-left');
+        });
+      }
+
+      let routeFound = false;
+      let attempts = 0;
+      const maxAttempts = 10;
+
+      while (!routeFound && attempts < maxAttempts) {
+        const angle = Math.random() * Math.PI * 2;
+        const dx = Math.cos(angle) * (roundTrip ? distance / 2 : distance);
+        const dy = Math.sin(angle) * (roundTrip ? distance / 2 : distance);
+        const waypoint = [startPoint[0] + dx / (111320 * Math.cos(startPoint[1] * Math.PI / 180)), startPoint[1] + dy / 110540];
+
+        if (stores) {
+          const store = await findNearestStore(startPoint);
+          if (store) {
+            directions.setOrigin(startPoint);
+            directions.addWaypoint(0, store.center);
+            directions.setDestination(roundTrip ? startPoint : waypoint);
+            destinationPoint = store.center;
           } else {
-            console.log("Route distance does not meet the requirement. Adjusting...");
-            attempts++;
+            alert("No convenience stores found nearby.");
+            return;
           }
+        } else {
+          directions.setOrigin(startPoint);
+          directions.setDestination(roundTrip ? startPoint : waypoint);
+          destinationPoint = roundTrip ? startPoint : waypoint;
         }
 
-        if (!routeFound) {
-          alert("Unable to find a suitable route. Please try again.");
+        const route = await new Promise((resolve) => {
+          directions.on('route', (e) => {
+            resolve(e.route[0]);
+          });
+        });
+
+        if (route.distance >= distance * 0.8 && route.distance <= distance * 1.2) {
+          routeFound = true;
+          if (hills) {
+            map.setLayoutProperty('hillshading', 'visibility', 'visible');
+          } else {
+            map.setLayoutProperty('hillshading', 'visibility', 'none');
+          }
+          console.log(`Route distance: ${route.distance} meters`);
+        } else {
+          console.log("Route distance does not meet the requirement. Adjusting...");
+          attempts++;
         }
-      });
+      }
+
+      if (!routeFound) {
+        alert("Unable to find a suitable route. Please try again.");
+      }
     });
 
+    async function findNearestStore(startPoint) {
+      const response = await fetch(`https://api.mapbox.com/geocoding/v5/mapbox.places/convenience%20store.json?proximity=${startPoint[0]},${startPoint[1]}&limit=1&access_token=${mapboxgl.accessToken}`);
+      const data = await response.json();
+      return data.features.length ? data.features[0] : null;
+    }
+
     document.getElementById('open-google-maps').addEventListener('click', () => {
-      const googleMapsUrl = `https://www.google.com/maps/dir/?api=1&origin=${startPoint[1]},${startPoint[0]}&destination=${startPoint[1]},${startPoint[0]}&travelmode=walking`;
+      if (startPoint.length === 0 || destinationPoint.length === 0) {
+        alert("Please generate a route first.");
+        return;
+      }
+      const googleMapsUrl = `https://www.google.com/maps/dir/?api=1&origin=${startPoint[1]},${startPoint[0]}&destination=${destinationPoint[1]},${destinationPoint[0]}&travelmode=walking`;
       window.open(googleMapsUrl, '_blank');
     });
 
     document.getElementById('open-apple-maps').addEventListener('click', () => {
-      const appleMapsUrl = `http://maps.apple.com/?saddr=${startPoint[1]},${startPoint[0]}&daddr=${startPoint[1]},${startPoint[0]}&dirflg=w`;
+      if (startPoint.length === 0 || destinationPoint.length === 0) {
+        alert("Please generate a route first.");
+        return;
+      }
+      const appleMapsUrl = `http://maps.apple.com/?saddr=${startPoint[1]},${startPoint[0]}&daddr=${destinationPoint[1]},${destinationPoint[0]}&dirflg=w`;
       window.open(appleMapsUrl, '_blank');
     });
   </script>