Kenneth L. Gaines. 27, of 218 Hogan Blvd., Mil) Hall, charged with homicide by a vehicle under the Pennsylvania motor vehicle code, pleaded not guilty to the charge. He is scheduled for jury selection and trial on Jan. 9,1978.The charges stem from an Aug. 13 head-on crash in which Lisa Smith, 18, of 416 E, Clinton St., Avis, was killed.Slate police said Gaines was passing two vehicles on the Renovo Road when his car slammed into a car operated by Elizabeth A. Smith, 17. Seven people were injured.