According to the Salem Police Department, a 48-year old Salem man was attacked in his front yard early Monday morning, as he attempted to stop three men from burglarizing his pickup truck.  Charles Casner of the 1300 block of North Dawley Street said he went to investigate, after hearing a commotion outside, and then saw three men in the process of removing the stereo from his truck that was parked in his front yard.  Casner was reportedly struck by the men as he tried to stop them.  The three then ran southbound from the scene, taking parts of the stereo system with them.  Casner was taken to Salem Township Hospital for treatment for injuries. He described the three men as two black males and one white male, all dressed in black.  Anyone with information on the incident is encouraged to call Salem police at 548-2232.