/**
  * function delete
  * @param int $id
  * @return boolean
  */
 public static function deleteUser($id = 0)
 {
     $id = (int) $id;
     if ($id < 1) {
         return false;
     }
     //delete role
     $ret = Da_Wrapper::delete()->table(self::DB_TABLE_ADMIN_USER)->where('id', $id)->execute();
     return $ret;
 }