unsubscribe.php and white page (no error)

[Jimmi08]

I am doing some testing and while displaying unsubscribe.php, the result was a white/empty page, but there is already a function for displaying the message about the wrong URL.

The reason is:

		if(empty($_GET['id']))
		{
			return;	       
		}

Is this intention or there is a missing line before return?
$this->invalidURL();

Thanks