Hi again Matt: The -2**31 does not seem to work on gfortran 4.2.1. I will stick with the other expression. Carlo -- Carlo U. Segre -- Professor of Physics Associate Dean for Special Projects, Graduate College Illinois Institute of Technology Voice: 312.567.3498 Fax: 312.567.3494 segre at iit.edu http://www.iit.edu/~segre segre at debian.org