TWMNextDlgCtl = packed record
  Msg: Cardinal;
  CtlFocus: Longint;
  Handle: WordBool;
  Unused: Word;
  Result: Longint;
end;

struct TWMNextDlgCtl {
  unsigned Msg;
  Longint CtlFocus;
  WordBool Handle;
  Word Unused;
  Longint Result;
};