Use of uninitialized value $sequence in concatenation (.) or string at startend-mod3.pl line 48, <FILE1> chunk 1.

Use of uninitialized value $sequence in substr at startend-mod3.pl line 49, <FILE1> chunk 1

##</code><code>##

  print "$sequence\n";
   my $sub_sequence = substr $sequence, ($startres - 11), ($endres - $startres + 11);