地理定位太慢了!我做错了什么?

这是我在测试页面中使用的简单代码:但是找到地址要花很长时间…为什么?我做错什么了吗?

<script src="http://maps.google.com/maps?hl=it&amp;file=api&amp;v=2&amp;sensor=true&amp;key=*xxxxxx*" type="text/javascript"></script>
<script type="text/javascript">
    var map;
    var geocoder;

    function addAddressToMap(response) 
    {
      if (!response || response.Status.code != 200) 
      {
        alert("Sorry, we were unable to geocode that address");
      } 
      else 
      {
        place = response.Placemark[0];
        point = new GLatLng(place.Point.coordinates[1], place.Point.coordinates[0]);

        document.getElementById('address').innerHTML = place.address;
      }
    }


    function searchGeolocation() 
    {
        if (navigator.geolocation) 
        {
            navigator.geolocation.getCurrentPosition(function(position) 
            {  
                geocoder = new GClientGeocoder();
                document.getElementById('latitude').innerHTML = position.coords.latitude;
                document.getElementById('longitude').innerHTML = position.coords.longitude;
                coordinates = position.coords.latitude+","+position.coords.longitude;
                geocoder.getLocations(coordinates, addAddressToMap);

            }); 
        }else
        {
            document.getElementById('latitude').innerHTML = "Unknown";
            document.getElementById('longitude').innerHTML = "Unknown";
            document.getElementById('address').innerHTML = "Unknown";
            alert("I'm sorry, but geolocation services are not supported by your browser.");    
        }
    }



</script>


<br/>
latitude = <div id="latitude">loading...</div>
<br/>
longitude = <div id="longitude">loading...</div>
<br/>
address = <div id="address">loading...</div>
<br/>


<script type="text/javascript">

    searchGeolocation();

</script>