在接收到新信息时添加多个标记

新来的。我在做一个能在地图上显示车辆位置的程序。#谷歌地图API V3。该程序将自动接收信息，如经度，纬度，速度，日期等从sql server (live)。我希望地图显示所有的标记(长&并在每次特定标记的位置发生变化时更新标记的位置。更新包括每个标记的信息窗口。我的问题是没有标记显示在地图上启动程序(晚&长了)。代码如下:

    var map = null;
    var Table_Pins = {};     // Liste des Pins affichées
    var Pos_Info = null;     // Dit sur quel marker se situe l'infobulle
    var Liste_Points = []; // Pour la mémorisation du tracé
    var route = null;
    var markers = [];
    //-----------------------------------------------------------------
        function initialize() {
            var mapOptions = {
                zoom: 15,
                center: new google.maps.LatLng(43.665, 7.052),
                mapTypeId: google.maps.MapTypeId.ROADMAP, //Type de carte
                mapTypeControl: true,
                panControl: true,
                zoomControl: true, //Zoom
                scaleControl: true, //Echelle
                scaleControlOptions: {
                position: google.maps.ControlPosition.LEFT_BOTTOM},
                streetViewControl: true
                } ;
            var map = new google.maps.Map(document.getElementById("map_canvas"), mapOptions);
            Affiche_Pin(map, myPin);
            }
            //------------------------
            // Ouverture du WebBrowser
            // -----------------------
        try { google.maps.event.addDomListener(window, 'load', initialize);}
        catch (ex){ alert("vous devez etre connecte a l'internet...");}

    // ------------------------------------------------------------------------------------
    //                          Affichage des véhicules
    // ------------------------------------------------------------------------------------
    var myPin =[];
    function Affiche_Pin(Lat, Long, immat, type, site, vitesse, date)
    { 
       myPin = Table_Pins[immat];

    if (typeof myPin != "undefined") 
     {
     myPin.setPosition(new google.maps.LatLng(Lat, Long))
      // La Pin est déja placée, on la déplace
      // -------------------------------------
       map = new google.maps.Map(document.getElementById('map')); 
       map.setCenter(new google.maps.LatLng(Lat, Long));
       map.setZoom(15);
       map.setMapTypeId(google.maps.MapTypeId.ROADMAP);
       if (Pos_Info == myPin) {
       var infowindow = new google.maps.InfoWindow({
       content: myPin.html, 
       position: new google.maps.LatLng(Lat, Long) });
       infowindow.open(map);
       } //end if (pos_info)
     }//end if (mypin)
     else{
     var imageMarqueur = new google.maps.MarkerImage('http://maps.google.com/mapfiles/kml/pal4/icon15.png',
          new google.maps.Size(32, 32),
          new google.maps.Point(0,0),
          new google.maps.Point(16, 32));
     var ombreMarqueur = new google.maps.MarkerImage('http://maps.google.com/mapfiles/kml/pal4/icon15s.png',
          new google.maps.Size(56, 32),
          new google.maps.Point(0,0),
          new google.maps.Point(16, 32));
     var vehlatlng = new google.maps.LatLng(Lat, Long) ;
     var marker = new google.maps.Marker({
     map: map,
     position: vehlatlng,
     icon: imageMarqueur,
     shadow: ombreMarqueur       });
     var infowindow = new google.maps.InfoWindow({
     content: 'Véhicule :' + immat + ' ' + '<br>' +
            'Site : ' + site + '<br>' +
            'Type : ' + type + '<br>' +
            'Vitesse : ' + vitesse + ' km/h' + '<br>' +
            'Date : ' + date + '<br>',  
     position: vehlatlng });
      }//end else
     // Evenement "Click" et "infowindowopen" du marker
     // ---------------------------
      google.maps.event.addListener(marker, 'click', function() {
          if(lastOpenInfoWin) lastOpenInfoWin.close();
          lastOpenInfoWin = infowindow;
          infowindow.open(marker.get('map'), marker); 
          Pos_Info = marker;});
    Table_Pins[immat] = marker;
      markers.push(marker);
     marker.setMap(map);

  }//end function affiche_pin

"immat"为车辆id，vitesse的意思是速度。