How to prevent sites to access to other site folder?
===

please help me
I'm working on an asp.net application have a main site and sub sites like this :

site.com/parent

site.com/parent/child1

site.com/parent/child2

Any page on parent site can access to child1 and child2 files and copy, delete them

but the problem is : child1 also can access to child2 files and copy, delete them !

I want to prevent child1 site to access to child2 files

I am using asp.net and IIS 7.5

please help !