The quick-n-nasty way to stop black hole machines is to submit a job that just sleeps forever. Cheers, Guy -- Dr. Guy Coates, Informatics System Group The Wellcome Trust Sanger Institute, Hinxton, Cambridge, CB10 1HH, UK Tel: +44 (0)1223 834244 x 6925 Fax: +44 (0)1223 496802