I am trying to build a small mvc-based application.

How do I call a method in a class based on a query string?

For example, the $_GET query string is being set as load_master_form

http://www.domain.com/settings/load_master_form

And to call the method within the settings class, I am doing:

function __construct(){
    $this->{$_GET['method']}();
}

But obviously that doesn't work - it just isn't possible to load a method like that. So how would it be done?