initMap.js

function initMap() {
    map = new google.maps.Map(document.getElementById('map'), {
        // center: {lat: 42.9456, lng: -122.2},
        // center: { lat: 10.7663468, lng: 106.6589143 },
        zoom: 14
    });
    infoWindow = new google.maps.InfoWindow;

    // Geolocation.
    if (navigator.geolocation) {
        navigator.geolocation.getCurrentPosition(function(position) {
            var pos = {
                lat: position.coords.latitude,
                lng: position.coords.longitude
            };

            infoWindow.setPosition(pos);
            infoWindow.setContent('Location found.');
            infoWindow.open(map);
            map.setCenter(pos);
        }, function() {
            handleLocationError(true, infoWindow, map.getCenter());
        });
        loadMarkers();
            setInterval(function(){
                console.log("loadMarkers");
                loadMarkers();
            }, 30000);
    } else {
        // Browser doesn't support Geolocation
        handleLocationError(false, infoWindow, map.getCenter());
    }

    // loadMarkers();
    // setInterval(function(){
    //     console.log("loadMarkers");
    //     loadMarkers();
    // }, 30000);
}