function load() {
  if (GBrowserIsCompatible()) {
    var map = new GMap2(document.getElementById("map"));
    map.addControl(new GLargeMapControl());
    map.addControl(new GMapTypeControl());
    map.setCenter(new GLatLng(40.77,-73.93), 11);

    GDownloadUrl("map.xml", function(data) {
      var xml = GXml.parse(data);
      var markers = xml.documentElement.getElementsByTagName("marker");
      var points = [];
      var color = '#FF0000';
      last_zip = parseFloat(markers[0].getAttribute("zip"));
      for (var i = 0; i < markers.length; i++) {
        if (parseFloat(markers[i].getAttribute("zip")) != last_zip) {
           map.addOverlay(new GPolygon(points,color,1,0,color,.7));
           var points = [];
           points.push(new GLatLng(parseFloat(markers[i].getAttribute("lat")),parseFloat(markers[i].getAttribute("lng"))));
           last_zip = parseFloat(markers[i].getAttribute("zip"));
         } else {
           points.push(new GLatLng(parseFloat(markers[i].getAttribute("lat")),parseFloat(markers[i].getAttribute("lng"))));
           last_zip = parseFloat(markers[i].getAttribute("zip"));
         }
         color = markers[i].getAttribute("color");
       }
    });
  }
}