Update marker in real time

Question

I need fetch the new position from json file which will be updated at regualr intervals in order to update it on the map without reloading the whole page repeatedly. How can I do without using Ajax

                 if (GBrowserIsCompatible()) {
                 //==add controls
                 var map = new GMap(document.getElementById("map"));
                 map.addControl(new GLargeMapControl());
                 map.addControl(new GMapTypeControl());
                 map.setCenter(new GLatLng(-29.870879, 30.977258),15);

                 var htmls = [];
                 var i = 0;

                 //create marker and set up infoWindow
                 function createMarker(point,ID,name) {
                 var marker = new GMarker(point);
                 GEvent.addListener(marker, "click", function() {
                 marker.openInfoWindowHtml(ID+"<br/>Name: " +name);

                 });

                  return marker;
                }



            process_Data = function(doc) {
                 //parse json file
                 var jsonData = eval('(' + doc + ')');

                 // ======== Plots the markers on Google Maps============

                   for (var i=0; i<jsonData.markers.length; i++) {
                       var point = new GLatLng(jsonData.markers[i].lat, jsonData.markers[i].lng);
                        var marker = createMarker(point,jsonData.markers[i].ID,jsonData.markers[i].name);
                       map.addOverlay(marker);

                       }
                     }

                      GDownloadUrl("points.json", process_Data);

                      }

Answer 1

var marker;

// every 10 seconds
setInterval(updateMarker,10000);

function updateMarker() {
   $.post('/path/to/server/getPosition',{}, function(json) {
      var LatLng = new google.maps.LatLng(json.latitude, json.longitude);
      marker.setPosition(LatLng);
   });
}