I have three completely different(!) but workable solutions. Thanks much for your help. =Randy= R. Zelick email: zelickr at pdx.edu Department of Biology voice: 503-725-3086 Portland State University fax: 503-725-3888 mailing: P.O. Box 751 Portland, OR 97207 shipping: 1719 SW 10th Ave, Room 246 Portland, OR 97201