Dera Axel, that worked perfectly. Thanks very much! I tried to find answers at old posts, but for some reason I didn't find this one. Cheers, Priscila -- Priscila Grynberg, D.Sc.- Bioinformatics Laboratório de Genética Bioquímica Universidade Federal de Minas Gerais Tel: +55 31 3409-2628 CV: http://lattes.cnpq.br/8808643075395963 [[alternative HTML version deleted]]