$tasks{$URL} = $URL;

while (keys(%tasks) != 0) {
  foreach $key (keys (%tasks)) {
   if (!$opt_v) {
     print "#";
   } else {
     print "checking $key\n";
   }
    check_page($key);
    delete $tasks{key};
  }
}


sub check_page{
  unless (defined ($content = get $_[0])) {
    print "\n\n NASTY ERROR! \n\n bad link: $_[0]\n\n\n";
    return;
  }

  my $parser = XML::Parser->new(ErrorContext => 2, Style => "Tree");
  my $xso = XML::SimpleObject->new( $parser->parse($content) ) or die "could not parse!";

  check_tag($xso);

# output the information

  foreach $file (keys %soundfiles) {
    print "\n BAD ".$file." called in $_[0]\n";
  }

  foreach $link (keys %links) {
    next if make_url($link) =~ /$_[0]/ ;
    next if $link =~ /^#/ ;
    $tasks{make_url($link)} = make_url($link);
        print "checking ".make_url($link)."\n";
  }
}

sub check_tag{
  foreach my $tag($_[0]->children()) {
   if ($tag->name =~ /audio/) {
    build_audio($tag);
   }
   if ($tag->name =~ /goto/) {
    $links{$tag->attribute('next')} = "goto";
   }
    check_tag($tag);
  }
}

sub make_url {
  if ($_[0] =~ /http:/) {
    return $_[0];
  } elsif ($_[0] =~ /^#/) {
    return $_[0];
  } else {
    return $base_url.$_[0];
  }
}

sub build_audio {
  if (!exists $soundfiles{$_[0]->attribute('src')}) {
   unless (head(make_url($_[0]->attribute('src')))) {
     $soundfiles{make_url($_[0]->attribute('src'))} = "BAD";
   }
  }
}