如何获得当前时间的毫秒和秒 ( 积分: 30 )

请举个例子说明..

unit Unit1;

interface

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

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

var
Form1: TForm1;

implementation

{$R *.dfm}


procedure TForm1.Button1Click(Sender: TObject);
var
wdHo,wdMi,wdSe,wdMSe: Word;
begin
DecodeTime(Now,wdHo,wdMi,wdSe,wdMSe);
ShowMessage(Format('当前时间是:%d时%d分%d秒%d毫秒',[wdHo,wdMi,wdSe,wdMSe]));
end;

end.

请问我只要秒和毫秒 DecodeTime(Now,wdHo,wdMi,wdSe,wdMSe);怎么写呀?
再把它转换为双精度...

接受答案了.