how can I export the content of a subgrid? I am having trouble even putting the export icon in the footer of the subgrid.

I can export just the main level.

my code is something like this

$dg1 = new C_DataGrid('….');
$dg1 -> enable_export('EXCEL');
$dg2 = new C_DataGrid('…');
$dg2 -> enable_export('EXCEL');
$dg1 -> set_subgrid($dg2, 'Idx');
$dg1 -> display();

thank you,
Maria