if (GBrowserIsCompatible()) {
      // this variable will collect the html which will eventualkly be placed in the sidebar
      var sidebar_html = "";
    
      // arrays to hold copies of the markers and html used by the sidebar
      // because the function closure trick doesnt work there
      var gmarkers = [];

      // ==================================================
      // A function to create a tabbed marker and set up the event window
      // This version accepts a variable number of tabs, passed in the arrays htmls[] and labels[]
      function createTabbedMarker(point,label,tabs,icon) {
        var marker = new GMarker(point,icon);
        var marker_num = gmarkers.length;
        marker.marker_num = marker_num;
        marker.tabs = tabs;
        gmarkers[marker_num] = marker;
        
        GEvent.addListener(gmarkers[marker_num], "click", function() {
          marker.openInfoWindowTabsHtml(gmarkers[marker_num].tabs);
        });
return marker;
      }
      // ==================================================
      


      // This function picks up the click and opens the corresponding info window
      function myclick(i) {
         GEvent.trigger(gmarkers[i], "click");
      }

function getNodeValue(Element) {
if ((Element.length>0) && Element[0] && Element[0].firstChild && Element[0].firstChild.nodeValue)
   return Element[0].firstChild.nodeValue;
}


      // create the map
      // var map = new GMap2(document.getElementById("map"));
      var map = new GMap(document.getElementById("map"));
      map.addControl(new GLargeMapControl());
      map.addControl(new GMapTypeControl());
      map.centerAndZoom(new GPoint(10, 40), 15);


      // Read the data from example.xml
      var request = GXmlHttp.create();
      var filename = "agents.xml";
      request.open("GET", filename, true);
      request.onreadystatechange = function() {
        if (request.readyState == 4) {
if ((request.status != 200) && (request.status != 304)) {
alert("file not found: "+filename);
return;
}
          var xmlDoc = request.responseXML;
          // obtain the array of markers and loop through it
          var markers = xmlDoc.documentElement.getElementsByTagName("marker");
          // alert("processing "+markers.length+" markers");
          for (var i = 0; i < markers.length; i++) {
            // obtain the attributes of each marker
            var lat = parseFloat(markers[i].getAttribute("lat"));
            var lng = parseFloat(markers[i].getAttribute("lng"));
            var label = markers[i].getAttribute("label");
            // alert("point["+i+"] label="+label+":("+lat+", "+lng+")");
            if (isNaN(lat) || isNaN(lng)) {
               alert("bad point "+i);
               continue;
            }
            var point = new GLatLng(lat,lng);
            // get the tab info
            tabInfo = markers[i].getElementsByTagName("tab");
            tabs = new Array();
            if (tabInfo.length > 0) {
               // alert("processing "+tabInfo.length+" tabs");
               for (var j = 0; j < tabInfo.length; j++) {
                  var tabLabel = getNodeValue(tabInfo[j].getElementsByTagName("label"));
                  var tabHtml = getNodeValue(tabInfo[j].getElementsByTagName("contents"));
                  // alert("point["+i+"] tab["+j+"] label="+tabLabel+", contents="+tabHtml);
                  if ((j==0) && (tabInfo.length > 2)){ //  adjust the width so that the info window is large enough for this many tabs
                      tabHtml = '<div style="width:'+tabInfo.length*88+'px">' + tabHtml + '</div>';
                  }
                  tabs.push(new GInfoWindowTab(tabLabel,tabHtml));
               }
            } else { alert("no tabs point "+i); }      

            // create the marker
            var marker = createTabbedMarker(point,label,tabs);

            map.addOverlay(marker);
          }
}
      }
      request.send(null);
    }

    else {
      alert("Sorry, the Google Maps API is not compatible with this browser");
    }