sub mysort_asc {
  $hash{$a}{$orderby} <=> $hash{$b}{$orderby}
  ||
  $hash{$a}{$orderby} cmp $hash{$b}{$orderby}
}
sub mysort_desc {
  $hash{$b}{$orderby} <=> $hash{$a}{$orderby}
  ||
  $hash{$b}{$orderby} cmp $hash{$a}{$orderby}
}

my $sort_func = $direction eq 'DESC' ? \&mysort_desc : \&mysort_asc;
foreach my $id (sort { &$sort_func } keys %hash)
{
  #...
}