function load(vlat, vlng, vzoom, maptype) {

  function displaySurveys(data){
      var xmlDoc = GXml.parse(data);
      // extract an array of markers
      var markers = xmlDoc.documentElement.getElementsByTagName("placement");
          
      // reset the side_bar
      side_bar_html = '';
          
      for (var i = 0; i < markers.length; i++) {
        // obtain the attribues of each marker
        var image = markers[i].getAttribute("image");
        var spatialreference= markers[i].getAttribute("spatialreference");
        var copyright= markers[i].getAttribute("copyright");

        // create the marker
        side_bar_html += "<p><b>" + image + "</b> Copyright: " + copyright + " Coordinate system: " + spatialreference + "</p>";
      }
      // put the assembled side_bar_html contents into the side_bar div
      document.getElementById("side_bar").innerHTML = side_bar_html;
  }
  GDownloadUrl("listsurveys.py", displaySurveys)
}