if (GBrowserIsCompatible()) {
      // this variable will collect the html which will eventualkly be placed in the side_bar
       var side_bar_html = "";
    
      // arrays to hold copies of the markers and html used by the side_bar
      // because the function closure trick doesnt work there
      var gmarkers = [];
      var htmls = [];
      var i = 0;
      
       
      
      // === Create an associative array of GIcons() ===
      var gicons = [];
      gicons["mk"] = new GIcon(G_DEFAULT_ICON, "images/map/mk_marker.png");
      gicons["ib"]  = new GIcon(G_DEFAULT_ICON, "images/map/ib_marker.png");
      gicons["rs"]  = new GIcon(G_DEFAULT_ICON, "images/map/rs_marker.png");
      
      gicons.mk.shadow = "images/map/shadow_marker.png";
      gicons.mk.iconSize = new GSize(33, 56);
      gicons.mk.shadowSize = new GSize(90, 56);
      gicons.mk.iconAnchor = new GPoint(16, 56);
      gicons.mk.infoWindowAnchor = new GPoint(15, 59);
      
      gicons.ib.shadow = "images/map/shadow_marker.png";
      gicons.ib.iconSize = new GSize(33, 56);
      gicons.ib.shadowSize = new GSize(90, 56);
      gicons.ib.iconAnchor = new GPoint(16, 56);
      gicons.ib.infoWindowAnchor = new GPoint(15, 59);
      
      gicons.rs.shadow = "images/map/shadow_marker.png";
      gicons.rs.iconSize = new GSize(33, 56);
      gicons.rs.shadowSize = new GSize(90, 56);
      gicons.rs.iconAnchor = new GPoint(16, 56);
      gicons.rs.infoWindowAnchor = new GPoint(15, 59); 


      // A function to create the marker and set up the event window
      function createMarker(point,name,html,icontype) {
        
        
        
        // === create a marker with the requested icon ===
        var marker = new GMarker(point, gicons[icontype]);
        GEvent.addListener(marker, "click", function() {
          marker.openInfoWindowHtml(html);
        });
        // save the info we need to use later for the side_bar
        gmarkers[i] = marker;
        htmls[i] = html;
        // add a line to the side_bar html
        side_bar_html += '<a href="javascript:myclick(' + i + ')">' + name + '</a><br>';
        i++;
        return marker;
      }


      // This function picks up the click and opens the corresponding info window
      function myclick(i) {
        gmarkers[i].openInfoWindowHtml(htmls[i]);
      }


      // create the map
      var map = new GMap2(document.getElementById("map"));
      map.addMapType(G_PHYSICAL_MAP);
      map.addControl(new GLargeMapControl());
      map.addControl(new GMapTypeControl());
      map.addControl(new GOverviewMapControl());
      map.setCenter(new GLatLng(33.454344,-111.88565), 14);


      // Read the data from example5.xml
      var request = GXmlHttp.create();
      request.open("GET", "xmlfiles/locations.xml", true);
      request.onreadystatechange = function() {
        if (request.readyState == 4) {
          var xmlDoc = GXml.parse(request.responseText);
          // obtain the array of markers and loop through it
          var markers = xmlDoc.documentElement.getElementsByTagName("marker");
          
          for (var i = 0; i < markers.length; i++) {
            // obtain the attribues of each marker
            var lat = parseFloat(markers[i].getAttribute("lat"));
            var lng = parseFloat(markers[i].getAttribute("lng"));
            var point = new GLatLng(lat,lng);
            var html = markers[i].getAttribute("html");
            var label = markers[i].getAttribute("label");
            // === read the icontype attribute ===
            var icontype = markers[i].getAttribute("icontype");
            

            
            
            
            
            
            // === create the marker, passing the icontype string ===
            var marker = createMarker(point,label,html,icontype);
            map.addOverlay(marker);
          }
          
          
          
          
          
          // put the assembled side_bar_html contents into the side_bar div
         //                     document.getElementById("side_bar").innerHTML = side_bar_html;
        }
      }
      request.send(null);
    }