<!--CodeS-->
unit Unit1;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, IdBaseComponent, IdComponent, IdTCPConnection,
IdTCPClient, IdHTTP, IdException;

type
TForm1 = class(TForm)
   Button1: TButton;
   IdHTTP1: TIdHTTP;
   procedure Button1Click(Sender: TObject);
private
   { Private declarations }
public
   { Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);

var
E: EIdException;

begin
try
   IdHTTP1.Head('http://www.delmadang.com/1234.gif');
   ShowMessage('파일있음');
except on E: EIdException do
   ShowMessage('파일이 없네...');
end;
  IdHTTP1.Disconnect;

end;

end.
<!--CodeE-->

출처 : http://www.delmadang.com/cwb-bin/CrazyWWWBoard.exe?db=dmdqa&mode=read&num=110277&page=1&backdepth=1