program Demo;

uses
  Windows, Messages;

var
  WinClass: TWndClassA;
  Inst, Handle, Button1, Label1, Edit1, hFont, WX, WY, WW, WH: Integer;
  Msg: TMsg;
  Password: String;

function CheckPassword(Value: String) : Boolean;
var
  Textlength: Integer;
  Text: PChar;
begin
  TextLength:= GetWindowTextLength(Edit1);
  GetMem(Text, TextLength + 1);
  try
    GetWindowText(Edit1, Text, TextLength + 1);
    Result:= (Text = Value);
    if not Result then
    begin
      MessageBoxA(Handle, 'Very bad... :)' , 'Password check', MB_OK);
      SetWindowText(Edit1, '');
      SetFocus(Edit1);
    end;
  finally
    FreeMem(Text, TextLength + 1);
  end;
end;

function WindowProc(hWnd, uMsg,   wParam,   lParam: Integer): Integer; stdcall;
var
  StrTmp: String;
begin
  StrTmp:= 'Password is correct :)' + #13 + 'Good luck ;)';
  Result:= DefWindowProc(hWnd, uMsg, wParam, lParam);
  if (lParam = Button1) and (uMsg = WM_COMMAND) then
    if CheckPassword (Password) then
    begin
      MessageBoxA(Handle, PChar(StrTmp) , 'Password check', MB_OK);
      Halt;
    end;
  if uMsg = WM_DESTROY then
    Halt;
end;

begin
  WW:= 305;
  WH:= 75;
  WX:= (GetSystemMetrics(SM_CYVIRTUALSCREEN) div 2) - (WH div 2);
  WY:= (GetSystemMetrics(SM_CXVIRTUALSCREEN) div 2) - (WW div 2);
  Password:= 'Over'; // Это типа пароль ;) :)))
  Inst:= hInstance;
  with WinClass do
  begin
    Style:= CS_CLASSDC or CS_PARENTDC;
    lpfnWndProc:= @WindowProc;
    hInstance:= Inst;
    hbrBackground:= color_btnface + 1;
    lpszClassName:= '_SGK_DEMO';
    hCursor:= LoadCursor(0, IDC_ARROW);
  end;
  RegisterClass(WinClass);
  Handle:= CreateWindowEx(WS_EX_TOPMOST, '_SGK_DEMO', 'Demo form _SGK',
                          WS_VISIBLE or WS_SIZEBOX or WS_CAPTION or WS_SYSMENU,
                          WX, WY, WW, WH, 0, 0, Inst, nil);
  Button1:= CreateWindow('Button', 'OK', WS_VISIBLE or WS_CHILD or BS_PUSHLIKE or
                         BS_TEXT, 216, 8, 75, 25, handle, 0, Inst, nil);
  Label1:= Createwindow('Static', '', WS_VISIBLE or WS_CHILD or SS_LEFT,
                        8, 12, 76, 13, Handle, 0, Inst, nil);
  Edit1:= CreateWindowEx(WS_EX_CLIENTEDGE, 'Edit', '', WS_CHILD or WS_VISIBLE or
                         WS_BORDER or ES_PASSWORD, 88, 8, 121, 21, Handle, 0, Inst, nil);
  hFont:= CreateFont(-11, 0, 0, 0, 400, 0, 0, 0, DEFAULT_CHARSET,
                     OUT_DEFAULT_PRECIS, CLIP_DEFAULT_PRECIS, DEFAULT_QUALITY,
                     DEFAULT_PITCH or FF_DONTCARE, 'MS Sans Serif');
  if hFont <> 0 then
  begin
    SendMessage(Button1, WM_SETFONT, hFont, 0);
    SendMessage(Label1, WM_SETFONT, hFont, 0);
    SendMessage(Edit1, WM_SETFONT, hFont, 0);
  end;
  SetWindowText(Label1, 'Enter password:');
  SetFocus(Edit1);
  UpdateWindow(Handle);

  while(GetMessage(Msg, Handle, 0, 0)) do
  begin
    TranslateMessage(msg);
    DispatchMessage(msg);
  end;
end.