HTML - textarea does not obey height

<!DOCTYPE html>
<html>
   <head>
      <title>Book.txt editor/preview for Bukkit Essentials</title>
      <link rel="stylesheet" type="text/css" href="book.css">
   </head>
   <body>
      <textarea class="bookeditor">Add or paste your book.txt here.</textarea>
   </body>
</html>