[Bioperl-l] problem parsing a newick format

[Chrysanthi A.]

Is the code below correct?? Why it does not print anything???
use strict;

use Bio::TreeIO;


my $input = new Bio::TreeIO(-fh =>"nexusCytochrome7R.newick",
                            -format => "newick");

while(my $tree = $input->next_tree){
    for my $node(grep{!$_->is_Leaf}$tree->get_nodes){
next if !$node->ancestor;
print "Node:", $node->id, "length:", $node->branch_length, " ";
for my $child($node->get_Descendents){
    print "child:", $child->id, "", $child->branch_length, " ";
}
    print "\n";
    }
}

Any ideas? I want to read a tree and mainly get the duplication events.
Could someone help me?

Thanks a lot,

Chrysanthi