This may be old news, if it's been posted before my apologies. John Burge with Pro-Gas at the Oct 2006 NESA meeting. <A HREF="http://www.nesanet.org/registration_list.asp?id=24&eid=3&tid=371" target="_blank">http://www.nesanet.org/registration_list.asp?id=24&eid=3&tid=371</A>