A State Police news release indicates that a 14-year-old boy was flown to Pittsburgh's Childrens Hospital for treatment of the injuries received in a traffic mishap, in northern Armstong County.     The un-named boy had been operating a motorcycycle on Lawsonham Road, just north of the intersection with Duncan Road, in Madison Township.     The boy lost control of the bike as it was going aound a curve.     The bike went off of the road and struck a guardrail.    (This mishap occurred just after 5:30 Sunday afternoon.)