$grid = new GridConnector($res);
$grid->enable_log("temp.log",true);
$grid->dynamic_loading(100);
/*$filter1 = new OptionsConnector($res);
$filter1->render_table("countries","item_id","item_id(value),item_nm(label)");
$grid->set_options("item_nm",$filter1);*/
$filter1 = new OptionsConnector($res);
$filter1->render_sql("SELECT DISTINCT SUBSTR(item_nm,1,2) as value from grid50","item_id","item_nm(value)");
$grid->set_options("item_nm",$filter1);