/// <summary>
        /// Remove mapping from current list
        /// </summary>
        /// <param name="sender"></param>
        /// <param name="e"></param>
        protected void btnRemove_Click(object sender, EventArgs e)
        {
            try
            {
                SPList list   = SPContext.Current.Web.Lists[this.ListId];
                Guid   listId = list.ID;

                // remove mapping
                _configService.RemoveMapping(this.Mapping.Id);

                // remove EventReceiver
                RemoveReceiverFromList(list, Constants.ReceiversNames.SYNC_DATA_ADDED);
                RemoveReceiverFromList(list, Constants.ReceiversNames.SYNC_DATA_UPDATED);
                RemoveReceiverFromList(list, Constants.ReceiversNames.SYNC_DATA_DELETING);
                list.Update();

                // update form to allow add new mapping
                ddlDbTables.Visible = true;
                lblTableName.Text   = string.Empty;
                this.UpdateMapperDataSource(ddlDbTables.Items[0].Value, null, null);
            }
            catch (Exception ex)
            {
                pnlError.Controls.Add(new Label {
                    Text = ex.Message, ForeColor = System.Drawing.Color.Red
                });
            }
        }