/// <summary>
        /// Raises the <see cref="E:System.Web.UI.Control.Init" /> event.
        /// </summary>
        /// <param name="e">An <see cref="T:System.EventArgs" /> object that contains the event data.</param>
        protected override void OnInit( EventArgs e )
        {
            base.OnInit( e );

            try
            {
                string groupMemberKey = PageParameter( "gm" );
                if ( string.IsNullOrWhiteSpace( groupMemberKey ) )
                {
                    ShowError( "Missing Parameter Value" );
                }
                else
                {
                    var groupMemberService = new GroupMemberService();
                    var groupMember = groupMemberService.GetByUrlEncodedKey( PageParameter( "gm" ) );
                    if ( groupMember == null )
                    {
                        ShowError();
                    }
                    else
                    {
                        groupMember.GroupMemberStatus = GroupMemberStatus.Active;
                        groupMemberService.Save( groupMember, CurrentPersonId );

                        nbMessage.NotificationBoxType = NotificationBoxType.Success;
                        nbMessage.Title = "Success";
                        nbMessage.Text = GetAttributeValue( "SuccessMessage" );
                    }
                }
            }
            catch (SystemException ex)
            {
                ShowError( ex.Message );
            }
        }