Index: app/controllers/post/save.php
===================================================================
--- app/controllers/post/save.php       (revision 1212)
+++ app/controllers/post/save.php       (working copy)
@@ -4,7 +4,8 @@
 }

 if (!$post->valid()) {
-       // TODO: more friendly error message
+       header('HTTP/1.1 403 Forbidden');
+       print_notice(i('Inputs is Empty.'), i('Fill out The Title and Body.'). ' ' . link_text('#', i('Back to Write Page'), array('onclick' => 'history.back();return false;')));
        exit;
 }

Index: lang/ko.php
===================================================================
--- lang/ko.php (revision 1212)
+++ lang/ko.php (working copy)
@@ -143,3 +143,6 @@
 $lang['Maintenance'] = '유지 보수';
 $lang['Site theme'] = '사이트 테마';
 $lang['Information'] = '정보';
+$lang['Inputs is Empty.'] = '입력란이 비었습니다.';
+$lang['Fill out The Title and Body.'] = '제목과 내용을 채워주세요.';
+$lang['Back to Write Page'] = '쓰기 페이지로 이동';

Index: app/models/metadata.php
===================================================================
--- app/models/metadata.php     (revision 1212)
+++ app/models/metadata.php     (working copy)
@@ -20,9 +20,11 @@
                $this->load();
        }
        function get($key) {
+               if (!$this->loaded) $this->load();
                return array_key_exists($key, $this->attributes) ? $this->attributes[$key] : '';
        }
        function set($key, $value) {
+               if (!$this->loaded) $this->load();
                if (!array_key_exists($key, $this->attributes)) {
                        insert('metadata', array('model' => $this->model->model, 'model_id' => $this->model->id, 'key' => $key, 'value' => $value));
                } else {
@@ -30,6 +32,11 @@
                }
                $this->attributes[$key] = $value;
        }
+       function remove($key) {
+               if (!$this->loaded) $this->load();
+               delete_all('metadata', "model='{$this->model->model}' AND model_id={$this->model->id} AND `key`=".$this->db->quote($key));
+               $this->reload();
+       }
        function reset() {
                delete_all('metadata', "model='{$this->model->model}' AND model_id={$this->model->id}");
        }
Index: lib/model.php
===================================================================
--- lib/model.php       (revision 1212)
+++ lib/model.php       (working copy)
@@ -125,5 +125,10 @@
                $this->metadata->model = &$this; // workaround for PHP4 -_-
                $this->metadata->set($key, $value);
        }
+
+       function remove_attribute($key) {
+               $this->metadata->model = &$this; // workaround for PHP4 -_-
+               $this->metadata->remove($key);
+       }
 }
 ?>