thanks for your advice...
I read the links you gave me and ended to put a line in the file "extcalendar.php"
I put the sentence in the beginning af the file (will you confirm if I am on the "right track", I am very new working with programming). regards Peter from Denmark:
defined('_VALID_MOS') or die('Direct Access to this location is not allowed.');
/*
**********************************************
ExtCalendar v2
Copyright (c) 2003-2005 Mohamed Moujami (Simo)
v1 originally written by Kristof De Jaeger
**********************************************
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
**********************************************
$File: extcalendar.php - Calendar view display$
File adapted from the file "calendar.php" in the original
ExtCalendar v2 software. Renamed and adapted to become a Mambo
Server component by Matthew Friedman.
Revision date: 5/22/2005
**********************************************
Get the latest version of ExtCalendar at:
http://extcal.sourceforge.net//**********************************************
*/
global $mosConfig_absolute_path;
and so on...