关于网页自动刷新的问题？(80分)

我想写一个程序，具体实现这种功能 ：
能够自动刷新网页，比如说：每隔5分钟就刷新一次，请问在delphi中怎么实现？
我在浏览资料后写了这样一段程序：

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, Comobj;

type
TForm1 = class(TForm)
Button1: TButton;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;
IEApp: Variant;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
begin
IEApp :=
IEApp.visible := true;
IEApp.Top := 0;
IEApp.Left := 0;
IEApp.width := screen.width;
IEApp.height := screen.height;
IEApp.Navigate('http://www.delphibbs.com');
end;

end.
但是使用CreateOLEObject('InternetExplorer.Application')的问题就是不能在当前已经打开的窗口里进行ie的控制，它总是会新打开一个ie窗口，请大家帮忙解决

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, OleCtrls, SHDocVw, StdCtrls;

type
TForm1 = class(TForm)
Button1: TButton;
WebBrowser1: TWebBrowser;
procedure FormCreate(Sender: TObject);
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.FormCreate(Sender: TObject);
begin
WebBrowser1.Navigate('http://www.delphibbs.com/delphibbs/listq.asp');
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
WebBrowser1.Refresh; //你需要应该是这个 他会帮你刷新
end;

end.

接受答案了.