Unnamed

<?phpfunction DisplayComic ($issue) {  if (strpos($issue, '.') != FALSE) {    return; // it could be ..  }  if (strpos($issue, '/') != FALSE) {    return; // we don't allow slashes ok  }  if (strpos($issue, '\\') != FALSE) {    return; // just to be sure  }  if (!file_exists('comic/'.$issue.'.png')) {    return; // doesn't exist  }  echo '<img src="comic/'.$issue.'.png"><br>';  $i = (int)$issue;  $prev = $i - 1;  $next = $i + 1;  if (file_exists('comic/'.$prev.'.png')) {    echo '<a href="?issue='.$prev.'">Previous</a>';  } else {    echo '<span class="color: gray">Previous</span>';  }  echo ' - ';  if (file_exists('comic/'.$next.'.png')) {    echo '<a href="?issue='.$next.'">Next</a>';  } else {    echo '<span class="color: gray">Next</span>';  }}if (!isset($_GET['issue'])) {  $iss = '1';} else {  $iss = $_GET['issue'];}DisplayComic($iss);?>