sub hashref_to_treeview {
	my $hashref = shift;
	my $treeview = shift; # Win32::GUI::Treeview object
	my $parent_node = shift || 0;
	
	return unless ref($hashref) eq 'HASH';
	
	for my $node ( sort keys %$hashref ) {
		my $new_node = $treeview->InsertItem(-text => $node, -parent => $parent_node);
		hashref_to_treeview($$hashref{$node}, $treeview, $new_node);
	}
}