Hi Abu. You can change the value of a field , after leaving another field.

$col = array();
$col["title"] = "Period from";
$col["name"] = "periodoDesde";
$col["edittype"] = "select";
$col["editoptions"] = array("value"=>'201607:07-2016;201606:06-2016;201605:05-2016;201604:04-2016;201603:03-2016;201602:02-2016;201601:01-2016;201512:12-2015;201511:11-2015;201510:10-2015;201509:09-2015;201508:08-2015');
$col["editable"] = true;
$col["show"] = array("list"=>false, "add"=>true, "edit"=>true, "view"=>false);
$col["editrules"] = array("required"=>true);
$cols[] = $col;

$col = array();
$col["title"] = "Period to";
$col["name"] = "periodoHasta";
$col["edittype"] = "select";
$col["editoptions"] = array("value"=>'201607:07-2016;201606:06-2016;201605:05-2016;201604:04-2016;201603:03-2016;201602:02-2016;201601:01-2016;201512:12-2015;201511:11-2015;201510:10-2015;201509:09-2015;201508:08-2015');
$col["editable"] = true;
$col["show"] = array("list"=>false, "add"=>true, "edit"=>true, "view"=>false);
$col["editrules"] = array("required"=>true);
$cols[] = $col;