Undeclared identifier: 'IWForm2'?

unit1.pas
----------------------------------------------------------------------
.....
implementation
{$R *.dfm}uses ServerController, login;......procedure TIWForm1.IWLink3Click(Sender: TObject);
begin
  WebApplication.ReleaseForm(Self);
  WebApplication.SetActiveForm(IWForm2);
end;
---------------------------------------------
login.pas
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unit login;interfaceuses
  Classes, SysUtils, IWAppForm, IWApplication, IWColor, IWTypes,
  IWCompButton, IWCompEdit, Controls, IWVCLBaseControl, IWBaseControl,
  IWBaseHTMLControl, IWControl, IWCompLabel;type
  TIWForm2 = class(TIWAppForm)
....
-----------------------------------------------
program Project1;uses
  Forms,
  IWMain,
  ServerController in 'ServerController.pas' {IWServerController: TIWServerController},
  Unit1 in 'Unit1.pas' {IWForm1: TIWFormModuleBase},
  UserSessionUnit in 'UserSessionUnit.pas' {IWUserSession: TIWUserSessionBase},
  DatamoduleUnit in 'DatamoduleUnit.pas' {DataModule1: TDataModule},
  IWDBStdCtrls in 'IWDBStdCtrls.pas',
  login in 'login.pas' {IWForm2: TIWAppForm};
{$R *.res}begin
  Application.Initialize;
  Application.CreateForm(TformIWMain, formIWMain);
  Application.Run;
end.