Xmlhttp open on an external ip

I have to access an asp page on a provider service and using the XML HTTP POST protocol to post XML to asp pages
I received from the service provider Ip address on their server
Name of Asp pages on their server where I post my xml query
My access Key to be inserted in a field in my xml file

The command I have to issue is

function XMLHTTP_run() {

var stringText=createXML();

var url='"http://Ipnumber/file.asp";
var xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
xmlHttp.Open("POST", url, false);
xmlHttp.send(unescape(stringText));
xmlHttp.responseText;

The above javascript returns an Authorization error when executing xmlHttp.Open

I call the Asps on my provider server from my server.

As I am a newbi please can you explain in simple words with an example how I can perform my requests without receiving the error message.
:confused:

Your problem is that the ASP file is not located on your server. You don't have access to call pages that are not in your server from obvious reasons.

What you should do is either create the file on your server or get the file you want to be on your server.
If this ASP file changes all the time and takes the information from that certain site, you could make an ASP file on your server which will read an XML file located on the other server and then display the information using the AJAX method.

Hope that helped.

Thanks for answering me

I cannot understand as the service provider I use has a lot of other companies accessing their Asps on their server from another server.