Thank you all for your mail replies and news postings. I will post of summary of the received mail when the traffic dies down. I appreciate your thoughtful and insightful comments. -- Stephen J. Hartley USENET: {decvax,ihnp4}!dartvax!uvm-gen!uvm-cs!hartley University of Vermont CSNET: hartley%uvm at csnet-relay (802) 656-3330, 862-5323