Two Janesville teenagers are facing armed robbery charges.  Janesville police say officers responded to a report of an armed robbery about 10:30 a.m. Tuesday in the 3800 block of Creekside Drive.  A news release indicates a woman reported being robbed at gun point while walking her dog.  Officers say the victim was able to get the license plate of the vehicle as it left the area.  The vehicle, which turned out to have been stolen the day before, was located around 1:30 p.m. near Wright Road and Stuart Street.  Police say 17-year-old Ishmail D. Gill and a 15-year-old boy were apprehended after a short car chase.  No one was injured in the incident.