/// <summary>
        /// Create a new role.
        /// </summary>
        /// <param name="role">Role that you want to create.</param>
        public void CreateRole(String roleName)
        {
            Role newRole = new Role();
            newRole.Role_Name = roleName;
            newRole.Role_IsDelete = false;

            //Check role name is exists.
            if (RD.GetRole(newRole.Role_Name) != null)
            {
                throw new Exception("This role is existed.");
            }
            int result = RD.CreateRole(newRole);
            if (result == -1)
            {
                throw new Exception("An error occurred while executing this operation.");
            }
        }
 /// <summary>
 /// Create new a role.
 /// </summary>
 /// <param name="role">Role that you want to create.</param>
 /// <returns>Return the number of rows affected or return -1 if occur exception.</returns>
 public int CreateRole(Role role)
 {
     return DBHelper.Instance.Insert(role);
 }
 /// <summary>
 /// Update a role.
 /// </summary>
 /// <param name="role">Role that you want to update.</param>
 /// <returns>Return the number of rows affected or return -1 if occur exception.</returns>
 public int UpdateRole(Role role)
 {
     return DBHelper.Instance.Update(role, String.Format("Role_Name = '{0}'", role.Role_Name));
 }