$xml_infos = "<?xml version='1.0' encoding='ISO-8859-1' standalone='yes'?><markers>\n";
    while ($row1 = mysql_fetch_array($result1))
    {
      $query2 = '
      SELECT DISTINCT(category_id)
        FROM '.IMAGE_CATEGORY_TABLE.'
          WHERE image_id = '.$row1['id'].'   
      '.($user['forbidden_categories'] != '' ? 'AND category_id NOT IN ('.$user['forbidden_categories'].')' : '').'
      ;';

      $result2 = pwg_query($query2);
      $row2 = mysql_fetch_array($result2);
      
      $query3 = '
      SELECT name
        FROM '.CATEGORIES_TABLE.'
          WHERE id = '.$row2['category_id'].';';

      $result3 = pwg_query($query3);
      $row3 = mysql_fetch_array($result3);

      $xml_infos .= '<marker ';
      $xml_infos.= encodeAttribute('id', $row1['id']);
      $xml_infos.= encodeAttribute('cat', $row2['category_id']);
      $xml_infos.= encodeAttribute('catname', ($row3['name']));
      $xml_infos.= encodeAttribute('lat', $row1['latitude']);
      $xml_infos.= encodeAttribute('long', $row1['longitude']);
      $xml_infos.= encodeAttribute('pointer', $row1['pointer']);
      $xml_infos.= encodeAttribute('shadow', $row1['shadow']);
      $xml_infos.= encodeAttribute('size', $row1['pointersize']);
      $xml_infos.= encodeAttribute('path', get_thumbnail_src($row1['path'], @$row1['tn_ext']));
      $xml_infos.= encodeAttribute('file', $row1['file']);
      $xml_infos.= encodeAttribute('name', htmlentities($row1['name']));
      $xml_infos .= " />\n";
    }
    $xml_infos.= '</markers>';

    file_put_contents ('./modules/google_maps/xml/'.$user['username'].'_data.xml',$xml_infos);

        // Creates a marker at the given point with the given number label
        function createMarker(point, cat, id, catname, path, file, pointer, shadow, size,name)
        {
          var icon = new GIcon();

          if (size == 0 ) 
          {
            icon.image = "{GMAP_DEFAULT_POINTER}";
            icon.shadow = "{GMAP_DEFAULT_SHADOW}";
            icon.iconSize = new GSize(12, {GMAP_DEFAULT_SIZE});
            icon.shadowSize = new GSize(22, {GMAP_DEFAULT_SIZE});
            icon.iconAnchor = new GPoint(6, {GMAP_DEFAULT_SIZE});
          } 
          else
          {
            icon.image = pointer;
            icon.shadow = shadow;
            icon.iconSize = new GSize(12, size);
            icon.shadowSize = new GSize(22, size);
            icon.iconAnchor = new GPoint(6, size);
          }

          icon.infoWindowAnchor = new GPoint(5, 1);
    
          var marker = new GMarker(point, icon);
          
          var msg = "<center><b>" +catname+ "</b></center><a href='./picture.php?/"+ id +"/category/"+cat+"' title="+name+"><img src='"+path+"'/></a><center><b>" +name+ "</b></center>";
          GEvent.addListener(marker, "click", function() {marker.openInfoWindowHtml(msg);});
          return marker;
        }        
                     
        // Download the data in data.xml and load it on the map. The format we
        GDownloadUrl(xmlfile, function(data) 
        {
          var xml = GXml.parse(data);
          var markers = xml.documentElement.getElementsByTagName("marker");
          for (var i = 0; i < markers.length; i++)
          {
            var point = new GLatLng(parseFloat(markers[i].getAttribute("lat")),
                                    parseFloat(markers[i].getAttribute("long")));
            map.addOverlay(createMarker(point, parseFloat(markers[i].getAttribute("cat")),
                                               parseFloat(markers[i].getAttribute("id")),
                                               markers[i].getAttribute("catname"),
                                               markers[i].getAttribute("path"),
                                               markers[i].getAttribute("file"),
                                               markers[i].getAttribute("pointer"),
                                               markers[i].getAttribute("shadow"),
                                               markers[i].getAttribute("size"),
                         markers[i].getAttribute("name")
                         ));
          }
        });        
      }

Internet Explorer renders polylines using VML - a vector markup
language.