Initial add comment implementation.

modules/comment/models/comment.php

@@ -18,4 +18,8 @@
  * Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA  02110-1301, USA.
  */
 class Comment_Model extends ORM {
+  var $validation_rules = array(
+    "author" => "required",
+    "email" => "required|valid_email",
+    "text" => "required");
 }