Xml caching?

1

I created a new slideshow in flash CS3 - AS3 but my code that I had for xml caching is barking at me and I am not sure what to do. The output window shows access to undefined property root. Any help appreciated


//added to help prevent XML caching
var xmlFile="images.xml";
var cacheBust:String = (_root._url.indexOf("file:") >= 0) ? "" : "?rn="+new Date().
getTime()+(Math.random()*100);
var src:String = xmlFile + cacheBust;
my_ssp.xmlFilePath= src;