Server side control of resource (html or image files) access

[giorgio_c]

I've this scenario:
1) user connect to IW server and a new session is started. The IW server return the main page with an HTML template including login fields.

2) user complete the login form and login with async event.
In CallBack function response the JS function getInfo() is called:

Code:

function getInfo() {
        $.get("img/item.html", function( my_var ) {
          $("#appInfoContent").html(my_var);
        });       
      }

This function load a resource (maybe html file or images etc..) and put it in an element.

My question is: how can i control server side the access to the resource file?
Server side have to check if user i logged or not, and if not logged it have to deny the "img/item.html" resource.
 
Many thanks.