private static string getAVehicleLicenseNumber(Garage i_Garage) { Console.WriteLine("-Please Type A License Number-"); string vehicleLicenseNumber = getANumericString(); while (!i_Garage.IsLicenseNumberAlrdyExists(vehicleLicenseNumber)) { Console.WriteLine("The Vehicle with the liecnse number {0}, is not exist", vehicleLicenseNumber); Console.WriteLine("Please Try Again!"); vehicleLicenseNumber = getANumericString(); } return(vehicleLicenseNumber); }