I'm not sure how to describe this, but basically I have a PHP class file:

class HelloHello {

   public function getSomeData($input_parameter){
     // code to retrieve data from the database
   }

   public function deleteSomeData($input_parameter){
    // code to delete data from the database
   }
}

This class is on the server and is part of the backend that connects with a database, and it's meant to be accessed by the frontend SWF only (not to be directly accessed). I've setup Flex to read this class and access it. But how do I make sure that someone doesn't develop a script that can call this php file directly and access its methods? For example using a script to add data in a fast automated way, or use the delete method directly, ouch.

Is this a legitimate concern, or this can't be done?