/// <summary>
        /// Create a service.
        /// </summary>
        /// <param name="serviceId">Id of service.</param>
        /// <param name="name">Name of service.</param>
        /// <param name="description">Description of service.</param>
        /// <param name="charge">Charge of service.</param>
        /// <param name="data">Image of service.</param>
        public void CreateService(Guid serviceId, String name, String description, String charge, String data)
        {
            try
            {
                Service service = new Service();
                service.Service_Id = serviceId;
                service.Service_Name = name;
                service.Service_Description = description;
                service.Service_Charge = SecurityHelper.Instance.EncryptCryptography(charge, true);
                service.Service_Image = data;

                // Check name
                if (SD.GetService(service.Service_Name) != null)
                    throw new Exception(String.Format("This service with the name is '{0}' has already existed.", service.Service_Name));
                int result = SD.Create(service);
                if (result == -1)
                {
                    throw new Exception("An error occurred while executing this operation.");
                }
            }
            catch (Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }
 /// <summary>
 /// Create new a service
 /// </summary>
 /// <param name="service">Service that you want to create.</param>
 /// <returns>Return the number of rows affected or return -1 if occur exception.</returns>
 public int Create(Service service)
 {
     return DBHelper.Instance.Insert(service);
 }
 /// <summary>
 /// Update a service.
 /// </summary>
 /// <param name="service">The service that be updated.</param>
 /// <returns>Return the number of rows affected or return -1 if occur exception.</returns>
 public int Update(Service service)
 {
     return DBHelper.Instance.Update(service, String.Format("Service_Id = '{0}'", service.Service_Id));
 }