Greetings Wise ones :) I am making my first attempt at using a perl module (Bio::PrimerDesigner)and am needing some guidance. Here is the relevant part of my code, which is just me trying to copy the synopsis in the CPAN listing for this module. There is code prior the my $pd line and after the "use Bio::PrimerDesigner" that defines the %probe_hash in this script.

#!/usr/bin/env perl
use strict;
use File::Copy;
use warnings;
use diagnostics;
use Bio::PrimerDesigner;


my $pd = Bio::PrimerDesigner->new;

while ((my $probe_key, my $probe_value)=each(%probe_hash)) 
  {
#
# Define the DNA sequence, etc.
#
my $dna   = $probe_value;
my $seqID = $probe_key;

#
# Define design parameters (native primer3 syntax)
#
my %params = ( 
          PRIMER_NUM_RETURN   => 2,
          PRIMER_SEQUENCE_ID  => $seqID,
          SEQUENCE            => $dna,
          PRIMER_PRODUCT_SIZE => '500-600'
         );

#
# Design primers
#
my $results = $pd->design( %params ) or die $pd->error;

#
# Make sure the design was successful
#
if ( !$results->left ) {
  die "No primers found\n", $results->raw_data;
}

#
# Get results (single primer set)
#
my $left_primer  = $results->left;
my $right_primer = $results->right;
my $left_tm      = $results->lefttm;

#
# Get results (multiple primer sets)
#
my @left_primers  = $results->left(1..3);
my @right_primers = $results->right(1..3);
my @left_tms      = $results->lefttm(1..3);
}
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When I run this, I get the following error: No alias for 'PRIMER_PRODUCT_SIZE' at /script/location also, if I "print @left_primers;" will that print the contents of the array as expected?