The Columbia city clerk is checking to see if there are enough signatures on petitions to ask voters to change marijuana laws in the city. One petition calls for dismissing marijuana possession charges against people whose doctors have recommended they use it for medical purposes. The other petition calls for misdemeanor marijuana possession charges to be heard in city court, which could not impose jail time although it could levy a fine of as much as $250. A petition organizer says the campaign is designed to protect students caught with small amounts of marijuana. The petitions say the matter will be on the November ballot if the City Council does not pass ordinances matching the petition issues.