怎么在程序主界面启动前，弹出对话框，输入密码

Question

怎么在程序主界面启动前，弹出对话框，输入密码
procedure TMainForm.FormCreate(Sender: TObject);
begin
     PasswordDlg.ShowModal;
end;这样写程序出错！thanks in advance .

Answer 1

application.creatform(tPasswordDlg,PasswordDlg)
PasswordDlg.showmodal;

Answer 2

工程文件
program Project1;uses
  Forms,
  Unit1 in 'Unit1.pas' {Form1},
  Unit2 in 'Unit2.pas' {Form2};{$R *.res}begin
  Application.Initialize;
  Form2:=Tform2.Create(Application);
  try Form2.ShowModal;
  finally
     Form2.Free;
  end;
  Application.CreateForm(TForm1, Form1);
  Application.Run;
end.

Answer 3

begin
  Application.Initialize;
  Application.CreateForm(TfrmMain, frmMain);
  Application.CreateForm(TfrmLogin, frmLogin);
  FrmLogin.Show;
  While not gbLogin do   // gbLogin为全局变量, 窗体Login关闭时为True
    Application.ProcessMessages;
  Application.Run;
end.