A 19-year-old Madison man has been sentenced to serve time in the state penitentiary on a drug charge.  Aaron James Williams was sentenced Monday in Lake County Circuit Court to serve three years in the state penitentiary on one count of distributing marijuana in a drug-free zone.  Williams pleaded guilty to the charge in court last month as part of a plea agreement in which other felony drug charges against him were dismissed.  At the time of his plea, it was stated that Williams sold marijuana to a confidential informant in a parking lot within one-thousand feet of the Madison Public Library playground.  Circuit Judge Tim Tucker waived any fine or costs as part of Williams’ sentence, but did order him to pay 200-dollars in restitution and his court-appointed attorney fees.  Williams also received credit for 31 days he already has served in connection with the charges.