According to the pilot, he was "too high" during final approach to the runway, so he initiated a slip to loose altitude. As the Cessna 172 airplane touched down, the pilot "flared and tried to bleed off airspeed"; however, the airplane "ran out of runway," continued into the grass and impacted a fence. The pilot reported approximately 35 hours of total flight experience. Examination of the airplane by a Federal Aviation Administration inspector revealed no mechanical deficiencies.