I recently made not a few changes and additions to my web site so it will offer more information: more classroom suggestions, a listing of errata, addenda, and other such improvements. Hope you check it out. gg -- Genevra Gerhart http://www.wolfenet.com/~ggerhart/ 2134 E. Interlaken Bl. Tel. 206/329-0053 Seattle, WA 98112 ggerhart at wolfenet.com