procedure AppendLine(Control: HWND; const Text: string);
var
  SelStart, SelEnd: DWORD;
begin
  SendMessage(Control, EM_GETSEL, WPARAM(@SelStart), LPARAM(@SelEnd));
  SendMessage(Control, EM_SETSEL, 0, -1);
  SendMessage(Control, EM_SETSEL, -1, -1);
  SendMessage(Control, EM_REPLACESEL, WPARAM(True), LPARAM(PChar(sLineBreak + Text)));
  SendMessage(Control, EM_SETSEL, WPARAM(SelStart), LPARAM(SelEnd));
end;