Javascript and XML

Hello
I am having a problem loading an XML file into an external Javascript function.
What I am attempting to do is have one server (which I will not have access to) call an external javascript file on the other server.
The external javascript will load an xml file on the same server, generating a random record in the xml to read. The xml will have attributes in each record for an image name and a url.
Basically it is just a banner with properties randomly loaded from an xml file.
The problem I am having is that the javascript will not read the xml file once it has been run on the other server.
Here are the links
http://www.affordablecruisestours.com/xml/readwrite/touristAds.xml
http://www.thenextclick.ca/afford/test.html
http://www.affordablecruisestours.com/touristPostads.js

Right now I am just using two arrays to get the image and url but once I get the xml working I will replace the arrays with the xml.

Help on this would be GREATLY appreciated!