Officials in New Orleans are studying whether slot machines at Fair Grounds would conflict with a restriction in the city charter that limits gambling to a downtown casino.Voters in Orleans Parish approved slots for the track in 2003 after the track and Harrah's New Orleans Casino worked out an agreement so the machines at Fair Grounds wouldn't violate a state-granted monopoly on land-based gambling in the parish.Interim city council member David Payton has asked the city attorney for a legal opinion on whether the city needs to amend its charter to reflect the 2003 state legislation and corresponding popular referendum to allow up to 700 slot machines at Fair Grounds.A city charter change requires a simple majority vote by the public."If it is a casino, and we're talking about a land-based casino, I just wanted an opinion as to where this fits in," Payton said.The city is trying to work out details of the operation with Fair Grounds owner Churchill Downs Inc., which has applied to the Louisiana Gaming Control Board for a slots license. A spokeswoman for Churchill Downs declined comment.CDI purchased the racetrack last year. The first live Fair Grounds meet under CDI ownership began last November and concludes in late March. The company hopes to have slots operating by early 2006.Neighborhood groups in the historic area where Fair Grounds is located have raised concerns about the operation of slots at the track, including the possibility a slots casino could operate 24 hours a day.