Hello all, Thank you for your help. The problem has been fixed (and so promptly!) All the best, Fátima _______ Fátima Núñez, PhD Centre for Cancer Research (CIC) University of Salamanca-CSIC Campus Unamuno 37007 Salamanca Spain Phone: + 34 923 294802 Fax: + 34 923 294743 E-mail: fnunez at usal.es