Loading external text from within MC

Hey guys hows it going

I have been searchign for ages and I seem to have come up short on this. What I have is a simple menu system withn a MC. I want the buttons within that movie clip to load an external tex file into a dynamic text box, but it does not want to work for me.
The code I used previously worked when the buttons weren’t in the movie clip, but now they dont want to work. I have tried using teh tellTarget function to no avail, and now i am stuck. Here is the code i was using before

on (release) {
loadText = new loadVars();
loadText.load(“testing.txt”);
loadText.onLoad = function(success) {
if (success) {
// trace(success);
textbox.html = true;
textbox.htmlText = this.myNews;
}
};
}

Any ideas on how to modify that so it can be put on a button within a MC to load an external text file.

thanks heaps.

christian