[NumLock]

а

Код:

  if MessageBox(Handle, '', '', MB_OKCANCEL)=IDOK then

Код:

  if MessageBox(Handle, '', '', MB_YESNO)=IDYES then

IDOK и IDYES из Windows. вообще:

Код:

const
  { Dialog Box Command IDs }
  {$EXTERNALSYM IDOK}
  IDOK = 1;          ID_OK = IDOK;
  {$EXTERNALSYM IDCANCEL}
  IDCANCEL = 2;      ID_CANCEL = IDCANCEL;
  {$EXTERNALSYM IDABORT}
  IDABORT = 3;       ID_ABORT = IDABORT;
  {$EXTERNALSYM IDRETRY}
  IDRETRY = 4;       ID_RETRY = IDRETRY;
  {$EXTERNALSYM IDIGNORE}
  IDIGNORE = 5;      ID_IGNORE = IDIGNORE;
  {$EXTERNALSYM IDYES}
  IDYES = 6;         ID_YES = IDYES;
  {$EXTERNALSYM IDNO}
  IDNO = 7;          ID_NO = IDNO;
  {$EXTERNALSYM IDCLOSE}
  IDCLOSE = 8;       ID_CLOSE = IDCLOSE;
  {$EXTERNALSYM IDHELP}
  IDHELP = 9;        ID_HELP = IDHELP;
  {$EXTERNALSYM IDTRYAGAIN}
  IDTRYAGAIN = 10;
  {$EXTERNALSYM IDCONTINUE}
  IDCONTINUE = 11;