#!/usr/local/bin/perl

use warnings;
use strict;
use LWP::Simple;
use HTML::TreeBuilder;
my @files = (["http://microrna.sanger.ac.uk/cgi-bin/targets/v5/detail_view.pl?transcript_id=ENST00000226253", "a.txt"],);  
for my $duplet (@files) {
    mirror($duplet->[0], $duplet->[1]);
};
open DATA, 'a.txt';
my $html = do{local $/;<DATA>};
my $p = HTML::TreeBuilder->new;
$p->parse_content($html); # parse_content if you have a string

my @tds = $p->look_down(_tag => q{td}); # get a list of all the td tags
for my $td (@tds){
  my $bold = $td->look_down(_tag => q{b}); # look for a bold tag
  if ($bold=~ m/miR/ || $bold=~ m/let/){
    print $bold->as_text, qq{\n}; # if there is one print the text
  }
}
$p->delete; # when you've finished with it