php _construct ค่าที่ส่งไปไม่ยอมออก

class HelloName{

	protected $name;
	public function __construct($n){
		$this->name = $n;
		echo "start <br/>";
	}
	
	public function display(){
		echo "Test name :",$this->name;
	}
	
	public function __destruct(){
		unset($this->name);
		echo "<br/> Stop";
	}
}

$obj = new HelloName("soft");
$obj->display();