public function getUser()
    {
        if ($this->_user !== NULL)
            return $this->_user;
        else
		    $this->_user = Users::model()->findByAttributes(array('email'=>$this->username));

        if ($this->_user == NULL)
            $this->errorCode = YII_DEBUG ? self::ERROR_USERNAME_INVALID : self::ERROR_UNKNOWN_IDENTITY;

        return $this->_user;
    }