Dear You, just in case someone wants to know more about this, the topic was discussed in the Elk forum here: http://sourceforge.net/p/elk/discussion/897820/thread/4d0cf5e3/ Best regards, Pietro -- Pietro Bonfa' Dipartimento di Fisica e Scienze della Terra "Macedonio Melloni" Viale delle Scienze 7A 43124 Parma - Italy