var map;
    var markerArr = new Array();

//初始化google地图
function initialize() {
        var mapOptions = {
          center: new google.maps.LatLng(39.9, 116.40),
          zoom: 4,
          mapTypeId: google.maps.MapTypeId.ROADMAP
        };
        map = new google.maps.Map(document.getElementById("map_canvas"),
            mapOptions);
      }

//添加标记
function AddMarker(deviceName,lat,lng) 
    {
        var image = {
            url: \'image/carOver0.bmp\'
        };
          var myLatLng = new google.maps.LatLng(lat,lng);
          
          var beachMarker = new google.maps.Marker({
              position: myLatLng,
              map: map,
              icon: image,
              title:deviceName
          });
    
          markerArr.push(beachMarker);

        //弹窗
        var infowindow = new google.maps.InfoWindow({
              content: \'hello world!\'
          });

　　　　//为marker添加点击事件
        google.maps.event.addListener(beachMarker, \'click\', function() {
                infowindow.open(map,beachMarker);
          });
    } 

   
//删除标记
function RemoveMarker(deviceName)
    {
      var index;
      for (var i = 0; i < markerArr.length; i++) {
        var m = markerArr[i];//这个地方如果直接用markerArr[i].setMap(NULL)会把所有的标记都从地图删除，不懂，求指教！
        if (m.title == deviceName) {
           m.setMap(null);
           index = i;
        };
      };
      markerArr.splice(index,1);
    }

    
//更新标记位置
function UpdateCarLocation(deviceName,lat,lng)
    {
      var location = new google.maps.LatLng(lat,lng);

      for (var i = 0; i < markerArr.length; i++) {
        var marker = markerArr[i];
        if (marker.title == deviceName) {
          marker.setPosition(location);
        };
      };
    }