The following may be m interesting: ==> http://www-user.uni-bremen.de/~skupin/pdfanim/ Note: I am not the Author! ...Rolf -- || Rolf Niepraschk c/o Physikalisch-Technische Bundesanstalt || || Abbestr. 2-12; D-10587 Berlin, Germany || || Tel/Fax: ++49-30-3481-316/490, email: Rolf.Niepraschk at ptb.de ||