thanks for your reply.
I am really new in perl soany help is usefull.
I get a small error message though. first I create at he top of the script my $table which has a start and an end position, but then when I replace the print with the example you gave me I get an error that says that my clusters requires explicit package name. I don't really understand why this happens in this case, since the clusters have been declared.
Any ideas would be really usefull. Thanks