function getxtr()
{
  var req = null;
  if (window.XMLHttpRequest)
  {
    req = new XMLHttpRequest();
    if (req.overrideMimeType)
    {
      req.overrideMimeType("text/xml");
    }
  }
  else if (window.ActiveXObject)
  {
    try
    {
      req = new ActiveXObject("Msxml2.XMLHTTP");
    }
    catch (e)
    {
      try
      {
        req = new ActiveXObject("Microsoft.XMLHTTP");
      }
      catch (e)
      {
      }
    }
  }
  return req;
}

var iconblue = new google.maps.MarkerImage(
  "http://maps.google.com/mapfiles/ms/micons/purple-dot.png"
  , new google.maps.Size(32, 32), new google.maps.Point(0, 0)
  , new google.maps.Point(16, 32));
var iconyellow = new google.maps.MarkerImage(
  "http://maps.google.com/mapfiles/ms/micons/yellow-dot.png"
  , new google.maps.Size(32, 32), new google.maps.Point(0, 0)
  , new google.maps.Point(16, 32));
var iconred = new google.maps.MarkerImage(
  "http://maps.google.com/mapfiles/ms/micons/red-dot.png"
  , new google.maps.Size(32, 32), new google.maps.Point(0, 0)
  , new google.maps.Point(16, 32));
var iconorange = new google.maps.MarkerImage(
  "http://maps.google.com/mapfiles/ms/micons/orange-dot.png"
  , new google.maps.Size(32, 32), new google.maps.Point(0, 0)
  , new google.maps.Point(16, 32));

var center = null;
var map = null;
var currentPopup;
var bounds = new google.maps.LatLngBounds();
var markersArray = [];

function clearOverlays() {
  if (markersArray) {
    for (i in markersArray) {
      markersArray[i].setMap(null);
    }
  }
}
function addMarker(lat, lng, icon, info)
{
  var pt = new google.maps.LatLng(lat, lng);
  bounds.extend(pt);
  var marker = new google.maps.Marker({
    position: pt,
    icon: icon,
    map: map,
    title: info
  });
  markersArray.push(marker);
  var popup = new google.maps.InfoWindow({ //Infowindow
    content: "<span class=\"popup\">"+info+"</span>",
    maxWidth: 2000
  });
  google.maps.event.addListener(marker, "click", function() {
    if (currentPopup != null)
    {
      currentPopup.close();
      currentPopup = null;
    }
    popup.open(map, marker);
    currentPopup = popup;
  });
  google.maps.event.addListener(popup, "closeclick", function() {
    //map.panTo(center);
    currentPopup = null;
  });
}