* fix for exec sql in tutorial mode.

lib/dao/dao.class.php

@@ -5,7 +5,7 @@
  *
  * The author disclaims copyright to this source code.  In place of
  * a legal notice, here is a blessing:
- * 
+ *
  *  May you do good and not evil.
  *  May you find forgiveness for yourself and forgive others.
  *  May you share freely, never taking more than you give.
@@ -15,14 +15,14 @@ helper::import(dirname(dirname(__FILE__)) . '/base/dao/dao.class.php');
 /**
  * DAO类。
  * DAO, data access object.
- * 
+ *
  * @package framework
  */
 class dao extends baseDAO
 {
     public function exec($sql = '')
     {
-        if(isset($_SESSION['tutorialMode']) and $_SESSION['tutorialMode']) die();
+        if(isset($_SESSION['tutorialMode']) and $_SESSION['tutorialMode']) return true;
         return parent::exec($sql);
     }
 
@@ -36,7 +36,7 @@ class dao extends baseDAO
 /**
  * SQL类。
  * The SQL class.
- * 
+ *
  * @package framework
  */
 class sql extends baseSQL