Delphi-PRAXiS - Google Maps API

so nen großeß problem: Habe jetzt versucht den code in delphi 09 zu benutzten aber er zeigt nichts an im Webbrowser??

Kann mir jemand sagen was der fehler ist?
Delphi-Quellcode:
			unit Unit1;

interface

uses

  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,

  Dialogs, OleCtrls, SHDocVw, StdCtrls, ExtCtrls, XPMan, ComCtrls,MSHTML;

type

  TForm1 = class(TForm)

    XPManifest1: TXPManifest;

    CheckBoxTraffic: TCheckBox;

    WebBrowser1: TWebBrowser;

    procedure FormCreate(Sender: TObject);

    procedure CheckBoxTrafficClick(Sender: TObject);

  private

    { Private-Deklarationen }

     HTMLWindow2: IHTMLWindow2;

  public

    { Public-Deklarationen }

  end;

var

  Form1: TForm1;

implementation

uses

ActiveX;

{$R *.dfm}

const

HTMLStr: String =

'<html> '+

'<head> '+

'<meta name="viewport" content="initial-scale=1.0, user-scalable=yes" /> '+

'<script type="text/javascript" src="http://maps.google.com/maps/api/js?sensor=true"></script> '+

'<script type="text/javascript"> '+

''+

''+

'  var geocoder; '+

'  var map;  '+

'  var trafficLayer;'+

'  var bikeLayer;'+

''+

''+

'  function initialize() { '+

'    geocoder = new google.maps.Geocoder();'+

'    var latlng = new google.maps.LatLng(40.714776,-74.019213); '+

'    var myOptions = { '+

'      zoom: 13, '+

'      center: latlng, '+

'      mapTypeId: google.maps.MapTypeId.ROADMAP '+

'    }; '+

'    map = new google.maps.Map(document.getElementById("map_canvas"), myOptions); '+

'    trafficLayer = new google.maps.TrafficLayer();'+

'    bikeLayer = new google.maps.BicyclingLayer();'+

'  } '+

''+

''+

'  function codeAddress(address) { '+

'    if (geocoder) {'+

'      geocoder.geocode( { address: address}, function(results, status) { '+

'        if (status == google.maps.GeocoderStatus.OK) {'+

'          map.setCenter(results[0].geometry.location);'+

'          var marker = new google.maps.Marker({'+

'              map: map,'+

'              position: results[0].geometry.location'+

'          });'+

'        } else {'+

'          alert("Geocode was not successful for the following reason: " + status);'+

'        }'+

'      });'+

'    }'+

'  }'+

''+

''+

'  function GotoLatLng(Lat, Lang) { '+

'   var latlng = new google.maps.LatLng(Lat,Lang);'+

'   map.setCenter(latlng);'+

'   var marker = new google.maps.Marker({'+

'      position: latlng, '+

'      map: map,'+

'      title:Lat+","+Lang'+

'  });'+

'  }'+

''+

''+

'  function TrafficOn()   { trafficLayer.setMap(map); }'+

''+

'  function TrafficOff()  { trafficLayer.setMap(null); }'+

''+''+

'  function BicyclingOn() { bikeLayer.setMap(map); }'+

''+

'  function BicyclingOff(){ bikeLayer.setMap(null);}'+

''+

'  function StreetViewOn() { map.set("streetViewControl", true); }'+

''+

'  function StreetViewOff() { map.set("streetViewControl", false); }'+

''+

''+'</script> '+

'</head> '+

'<body onload="initialize()"> '+

'  <div id="map_canvas" style="width:100%; height:100%"></div> '+

'</body> '+

'</html> ';

procedure TForm1.CheckBoxTrafficClick(Sender: TObject);

begin

    if CheckBoxTraffic.Checked then

     HTMLWindow2.execScript('TrafficOn()', 'JavaScript')

    else

     HTMLWindow2.execScript('TrafficOff()', 'JavaScript');

 end;

procedure Tform1.FormCreate(Sender: TObject);

var

  aStream     : TMemoryStream;

begin

   WebBrowser1.Navigate('about:blank');

    if Assigned(WebBrowser1.Document) then

    begin

      aStream := TMemoryStream.Create;

      try

         aStream.WriteBuffer(Pointer(HTMLStr)^, Length(HTMLStr));

         //aStream.Write(HTMLStr[1], Length(HTMLStr));

         aStream.Seek(0, soFromBeginning);

         (WebBrowser1.Document as IPersistStreamInit).Load(TStreamAdapter.Create(aStream));

      finally

         aStream.Free;

      end;

      HTMLWindow2 := (WebBrowser1.Document as IHTMLDocument2).parentWindow;

    end;

end;

end.