opening files for website for shared folder

[ton]

Hi,

on my server I have a folder named files. This folder is no part of the
asp.net application where the websites runs. Is it possible to upload and
open to this folder or should the folder exist in the default website of the
application.

I've shared the folder also for web use, i've even added an anonymus user
and the aspnet user to get full access. But what ever i do. If I want to
open a file from this point I'll be prompted to identify myself or access is
forbiden. This is my function:

function SetImage(e,a) {
var scrn=document.getElementById(a);
window.open('http://server/files/D.jpg');
scrn.src='http://server/files/D.jpg';
// scrn.style.width='auto';
scrn.style.height='auto';
}

I think i have to set something in my iis but do not know where or what
thanx

ton