my $lproc = 621557;
my @sids  = get_sids($url, $pid, $lproc);

##</code><code>##

sub get_sids{
  
  my ($url, $pid, $lproc) = @_;
  my $page = 1;
  my $uri = URI->new($url);
  my ($i, @sids);

  while ($page){
    
    # build the uri
    $uri->query_form(page => $page, pid => $pid);
    my $uri_string = $uri->as_string;

    # get the content, check for success
    my $content = get $uri->as_string;
    die qq{LWP get failed: $!\n} unless $content;
    
    # build the tree
    my $t = HTML::TreeBuilder->new_from_content($content)
      or die qq{new from content failed: $!\n};
    
    # get a list of all anchor tags
    my @anchors = $t->look_down(_tag => q{a})
      or die qq{no tables found in : $!\n};
    
    # look at each anchor
    my $more = 1; # flag
    for my $anchor (@anchors){
      # get the href
      my $href = $anchor->attr(q{href});
      
      if ($href){

        # test for a sid in the query fragment
        my $uri = URI->new($href);
        my %q = $uri->query_form;
        my $sid = $q{sid};
        next unless $sid;
        
        # exit the while loop if it
        # is the last processed sid
        $more--, last if $sid == $lproc;
        
        # otherwise save it
        push @sids, $sid;
        
      }
    }
    
    last unless $more;
    
    # see if there is another page
    $page = get_next_page($t);
    
    # avoid accidental indefinite loops
    # hammering the server, adjust to suit
    die if $i++ > 5;
    
  }
  
  # send 'em back
  return @sids;
  
}