Police are searching for two men who they say robbed a livery cab driver at gunpoint in Canarsie. Police say the men were picked up at Avenue X and McDonald Avenue Saturday morning and driven to East 88th Street and Seaview Avenue. They say one of the suspects then pulled out a machine gun and demanded cash. Fernando Mateo, who belongs to the New York State Federation of Taxi Drivers, says the NYPD responded quickly to the incident, and that he has been calling for changes to taxi drivers' alert system. Police say the driver was not injured. Anyone with information is urged to call Crime Stoppers at 1-800-577-TIPS.