Hi Ola! you might also want to have a look at how the SPICE - browser does the das communication. http://www.efamily.org.uk/software/dasclients/spice/ devel_dasrequests.shtml Cheers, Andreas ----------------------------------------------------------------------- Andreas Prlic Wellcome Trust Sanger Institute Hinxton, Cambridge CB10 1SA, UK +44 (0) 1223 49 6891