use Tie::HashTree qw(hash_to_tree);
#my $tree = tie my %x, 'Tie::HashTree';
Tie::HashTree->new('tree');

sub new {
  my $pkg = shift;
  my($ppackage) = (caller)[0];   
  ${$ppackage.'::'.$_[0]} = tie %{$ppackage.'::'.$_[0]}, $pkg;
}

sub TIEHASH
{
        my ($class, $self) = @_;
        $self->{level} = "";
        $self->{name} = "top";
        $self->{top} = {};
        bless ($self, $class);
}