I accidently deleted the posting about this before I read it. Would someone be so kind as to send it to me. Thank you. Karen S. Browning, Ph.D. (email) brwnng at ccwf.cc.utexas.edu Dept. of Chemistry and Biochemistry (fax) 512-471-8696 The University of Texas at Austin (phone) 512-471-4562 Austin, TX 78712