$i = 0;
foreach $tab (@tabs) {
	j = 0;
	foreach $frnum (@FRs) {
		$tmp = $tab->Checkbutton(-text => $frnum,
					-variable => \@tab$i[$j],
					-command => sub { }
				)->pack(-side => 'top', -anchor => 'nw');
		$j++;
	}
	i++;
}