title: Retrieve geolocation in real time (HTML5)
body: <p>I have this code:</p>
  
  <pre><code>    var map;
      var geocoder;
  
      function initialize() {
        var mapOptions = {
          zoom: 18
        };
        map = new google.maps.Map(document.getElementById('map-canvas'),
            mapOptions);
  
        // Try HTML5 geolocation
        if(navigator.geolocation) {
          navigator.geolocation.getCurrentPosition(function(position) {
            var pos = new google.maps.LatLng(position.coords.latitude,
                                             position.coords.longitude);
  
            var marker = new google.maps.Marker({
                position: pos,
                map: map,
                title: 'Posizione Attuale'
  
            });
  
            map.setCenter(pos);
          }, function() {
            handleNoGeolocation(true);
            alert('GPS DISATTIVATO')
          },
          {enableHighAccuracy: true, timeout: 5000, maximumAge: 0});
        }else {
          // Browser doesn't support Geolocation
          handleNoGeolocation(false);
        }
        geocoder = new google.maps.Geocoder();
  
      }
  </code></pre>
  
  <p>I would like that when I walk on the street, the marker moves on the map in real time (like a navigator).
  How can I do that? I'm novice with the javascript language.</p>