Prevent external txts from caching

Hi all,
I know this question has been asked to death, I did search and tried to fix the problem with solutions from other posts, but none of them work!
Whenever i use a random generator to load the external texts it always ends up as undefined. This is the code i use to call the external txts

newstxt.html = true;
loadText = new LoadVars();
loadText.onLoad = function() {
newstxt.htmlText = this.newstext;

That loads everything fine, but caches.
Ive tried slapping the random number generators at the end like this

loadText.load("news.txt"+ Math.round(Math.random(1,999999)));

but then it becomes undefined. Anyone can shed some light for me?