// Code //
$col = array();
$col["title"] = "Client";
$col["name"] = "client_id";
$col["dbname"] = "clients.client_id";
$col["width"] = "100";
$col["align"] = "left";
$col["search"] = true;
$col["editable"] = true;
$col["edittype"] = "select";
# fetch data from database, with alias k for key, v for value

# on change, update other dropdown
$str = $g->get_dropdown_values("select client_id as k, name as v from clients");
$col["editoptions"] = array(
"value"=>$str,
"onchange" => array("sql"=>"select id as k, note as v from invheader WHERE client_id = '{client_id}'",
"update_field" => "note" )
);

$col["formatter"] = "select"; // display label, not value
$col["stype"] = "select";
$col["searchoptions"] = array("value" => ":;".$str);

$cols[] = $col;

$col = array();
$col["title"] = "Invoices";
$col["name"] = "note";
$col["width"] = "100";
$col["search"] = true;
$col["editable"] = true;
$col["edittype"] = "select";
$str = $g->get_dropdown_values("select id as k, note as v from invheader");
$col["editoptions"] = array("value"=>$str);

$col["editoptions"]["onload"]["sql"] = "select id as k, note as v from invheader WHERE client_id = {client_id}";
$col["stype"] = "select";
$col["searchoptions"] = array("value" => ":;".$str);

$cols[] = $col;
// Code //

When I onchange not working, help fix problem

thanks