DLL??

Hej jeg har rodet med denne her artikle

http://www.udvikleren.dk/vis_artikel.php4?id=47

og gjort som der står men den giver denne error nå jeg compiler

[Error] Project2.dpr(21): Undeclared identifier: 'frmDllForm'
[Error] Project2.dpr(21): Operator not applicable to this operand type
[Error] Project2.dpr(22): Undeclared identifier: 'TfrmDllForm'


her er min DLL kode


library Project2;

{ Important note about DLL memory management: ShareMem must be the
  first unit in your library's USES clause AND your project's (select
  Project-View Source) USES clause if your DLL exports any procedures or
  functions that pass strings as parameters or function results. This
  applies to all strings passed to and from your DLL--even those that
  are nested in records and classes. ShareMem is the interface unit to
  the BORLNDMM.DLL shared memory manager, which must be deployed along
  with your DLL. To avoid using BORLNDMM.DLL, pass string information
  using PChar or ShortString parameters. }

uses
  SysUtils,
  Classes,
  dllform in 'dllform.pas' {Form1};


procedure ShowDllForm; stdcall;
begin
  if frmDllForm = nil then
    frmDllForm := TfrmDllForm.Create(nil);
  frmDllForm.Show;
end;

function ShowDllFormModal: integer; stdcall;
begin
  if frmDllForm = nil then
    frmDllForm := TfrmDllForm.Create(nil);
  result := frmDllForm.ShowModal;
end;
procedure TfrmDllForm.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  Action := caFree;
  frmDllForm := nil;
end;

exports
  ShowDllForm,
  ShowDllFormModal;
{$R *.RES}

begin
end.