A vacation to the Cape turned ugly for an elderly couple from Pennsylvania when a man broke into their hotel room and robbed them at knifepoint Sunday, police said. The couple, 77 and 78 years old, were entering their hotel room at the Americas Best Value Inn at 206 Main St. in Hyannis at about 8:30 p.m. Sunday night when a man forced them into the room and began to fight with the male victim, said Barnstable Police Sergeant Sean Sweeney. The suspect, wielding a pocket knife, then demanded money from the woman, snatched her bag, and ran. No one was injured in the scuffle."