php – 搜索地址与google maps api v3上最近的现有地标之间的距

这是页面的代码：

<script type="text/javascript">
    var geocoder;
    var map; 
    var marker;
    var layers = [];
  function initialize() {
    geocoder = new google.maps.Geocoder ();
    var latlng = new google.maps.LatLng (41,-73.4);
    var myOptions = {
      zoom: 7,center: latlng,mapTypeId: google.maps.MapTypeId.ROADMAP
        }
      map = new google.maps.Map(document.getElementById("map_canvas"),myOptions);
      marker = new google.maps.Marker({map:map});


        layers[0] = new google.maps.KmlLayer('http://dl.dropbox.com/u/80233620/South-and-North-County-Trailway.kml',{preserveViewport: true});
        layers[1] = new google.maps.KmlLayer('http://www.nyc.gov/html/dot/downloads/misc/cityracks.kml',{preserveViewport: true});
        layers[2] = new google.maps.KmlLayer('http://dl.dropbox.com/u/80233620/NWS%20Radar%20Images.kmz',{preserveViewport: true});
    for (var i = 0; i < layers.length; i++) {
                layers[i].setMap(map);
              }
        }

    function codeAddress () {
        var address = document.getElementById ("address").value;
        geocoder.geocode ( { 'address': address},function(results,status)  {
        if (status == google.maps.GeocoderStatus.OK)  {
            map.setCenter(results [0].geometry.location);
            marker.setPosition(results [0].geometry.location);
            map.setZoom(14);
            } 
        else {
            alert("Geocode was not successful for the following reason: " + status);
                }
        }); 
                            }
    function toggleLayer(i) {
      if(layers[i].getMap() === null) {
        layers[i].setMap(map);
      }
      else {
        layers[i].setMap(null);}
    }

</script>