Geolocation.watchPosition()

navigator.geolocation.watchPosition(success[, error[, options]])

var id, target, options; function success(pos) { var crd = pos.coords; if (target.latitude === crd.latitude && target.longitude === crd.longitude) { console.log("Congratulations, you reached the target"); navigator.geolocation.clearWatch(id); } } function error(err) { console.warn("ERROR(" + err.code + "): " + err.message); } target = { latitude: 0, longitude: 0, }; options = { enableHighAccuracy: false, timeout: 5000, maximumAge: 0, }; id = navigator.geolocation.watchPosition(success, error, options);