Sorry about the type in the original subject line. I guess I should be more careful when recycling parts of other messages. Cheers, Lukas ------------------------------------------------------------------------------- Dr. Lukas Nellen | Email: lukas@teorica0.ifisicacu.unam.mx Depto. de Fisica Teorica, IFUNAM | Apdo. Postal 20-364 | Tel.: +52 5 622 5014 ext. 218 01000 Mexico D.F., MEXICO | Fax: +52 5 622 5015