WRAP attribute of textarea is not standard. That does not means it's useless, and you'd often want to set it, but then W3C validator will fail.

Here's a little trick to set it via Javascript, and to make it work under firefow which would not activate it if you just set it with textarea.wrap = ...:

<script type="text/javascript">
  document.ready = function() {
      var obj = document.all.code, pn = obj.parentNode, ns = obj.nextSibling;
      obj.wrap = 'off';
      pn.removeChild(obj);
      pn.obj(obj, ns);
    }
</script>

It will set the attribute, and rebuild the textarea to make the reticent browser take in account all parameters.