protected void AddTablesClick(object sender, EventArgs e)
        {
            // add metadata tables
            foreach (GridViewRow row in NewMetadataTablesGrid.Rows)
            {
                CheckBox cb = row.FindControl("AddMetaTableCheckBox") as CheckBox;
                if (cb.Checked)
                {
                    string        tableName = NewMetadataTablesGrid.DataKeys[row.RowIndex]["TABLE_NAME"].ToString();
                    MetadataTable biz       = new MetadataTable();
                    biz[MetadataTable.TableName_Field] = tableName;
                    biz.Save();
                }
            }

            // rebuild interface
            PopulateAttributeValues();
        }