diff --git a/dblayer.php b/dblayer.php
index 8851b68..372e55f 100644
--- a/dblayer.php
+++ b/dblayer.php
@@ -67,6 +67,11 @@ class dblayer extends PDO
       SQLite3 : PRAGMA TABLE_INFO('yourtable');
       MYSQL : SHOW COLUMNS FROM yourtable;*/
 
+  // TODO !!
+  /** Allow to modify tables if the definition is changed
+      Attention : SQLite don't supports adding Foreign keys without deleting all
+      the table, and re-import the datas (http://www.sqlite.org/omitted.html) */
+
   /** Connection to the database engine
       See http://fr2.php.net/manual/en/pdo.construct.php for the $dsn format
       @param string $dsn PDO Data Source Name
@@ -90,8 +95,18 @@ class dblayer extends PDO
     switch ($this->db->getAttribute(PDO::ATTR_DRIVER_NAME))
     {
     case "sqlite":
+      // Look at the right to write in database and in the directory
+      $file = substr ($dsn, 7);
+      if (! is_writeable (dirname ($file)))
+        throw new Exception (
+                      _("The directory for SQLite database is write protected"),
+                      500);
+      if (file_exists ($file) && ! is_writeable ($file))
+        throw new Exception (_("The SQLite database file is write protected"),
+                             500);
       // Force ForeignKeys support (disabled by default)
       $this->db->exec("PRAGMA foreign_keys = ON");
+      break;
     }
   }