XMLHttpRequest.open - Transforming XML in Mozilla

[admin]

I'm using a JavaScript which transforms XML/XSL into XHTML. The Script works perfectly when local, but when I upload to my site I get the following error message:

Error: uncaught exception: Permission denied to call method XMLHttpRequest.open

What changes from my local host to my remote one?

Script:

var xslStylesheet;
var xsltProcessor = new XSLTProcessor();
var myDOM;

var xmlDoc;

function Init(){

// load the xslt file, example1.xsl
var myXMLHTTPRequest = new XMLHttpRequest();
myXMLHTTPRequest.open("GET", "specials.xsl", false);
myXMLHTTPRequest.send(null);

xslStylesheet = myXMLHTTPRequest.responseXML;
xsltProcessor.importStylesheet(xslStylesheet);

// load the xml file, example1.xml
myXMLHTTPRequest = new XMLHttpRequest();
myXMLHTTPRequest.open("GET", "specials.xml", false);
myXMLHTTPRequest.send(null);

xmlDoc = myXMLHTTPRequest.responseXML;

var fragment = xsltProcessor.transformToFragment(xmlDoc, document);

document.getElementById("example").innerHTML = "";

myDOM = fragment;
document.getElementById("example").appendChild(fragment);
}