/// <summary>
 /// controller method calls database modifcation methods as well as controls the system message
 /// </summary>
 public string ModifyPolicy(int id, string Name, TypeOfVehicle TypeOfVehicle, PolicyType PolicyType, AgeRange AgeRange)
 {
     string returnMessage = "";
     DataBaseController controller = new DataBaseController();
     policy.Name = Name;
     policy.TypeOfVechile = TypeOfVehicle;
     policy.PolicyType = PolicyType;
     policy.AgeRange = AgeRange;
     returnMessage = controller.ModifyPolicy(policy, id);
     return returnMessage;
 }