public function update($source=null) {

        $this->rawgrade    = grade_floatval($this->rawgrade);

        $this->finalgrade  = grade_floatval($this->finalgrade);

        $this->rawgrademin = grade_floatval($this->rawgrademin);

        $this->rawgrademax = grade_floatval($this->rawgrademax);

        ////<grades_export event trigger

        $grade_to_update = new stdClass();

        $grade_to_update->courseid = $this->grade_item->courseid;

        $grade_to_update->userid = $this->userid;

        $grade_to_update->itemid = $this->grade_item->id;

        $grade_to_update->finalgrade = $this->finalgrade;

        events_trigger('grade_changed', $grade_to_update);

        ////>

	return parent::update($source);

    }