Steve: I just remembered, I get a division by zero error after quitting GDBIINT (after the interpolation is completed). Just wanted to let you know---Thanks Brett Brett Newkirk E-MAIL: address@hidden Office: ATG 424 Atmospheric Science/Geophysics Building Mailing Address: Department of Atmospheric Sciences, University of Washington Box 351640 Seattle, WA 98195-1640 Office Phone: (206) 685-2183