how to protect a controller function accessing by URL

[eluser]Tracker[/eluser]
I don't want to access "deleteItems" function directly like this.
http://localhost/Shop/deleteItems/3

it should only accessible if i will call
http://localhost/Shop/deleteShop/3

Your help will be appreciated...

Code:

class Shop extends Controller {

    function deleteShop()
    {
        $this-> deleteItems($shopId);
        //….

    }

    function deleteItems($shopId)
    {
        //….

    }
}