External text won't scroll

I’ve created a dynamic text box with buttons to scroll the text up and down. I’m not using the component that comes in flash mx. If I hard code text into the box, my scrolling functionality works. Now I’ve tried to take it a step further and load the text from an external .txt file using the following code:

loadText = new LoadVars();
loadText.onLoad = function(success) {
if (success) {
textcontainer.scroller.condenseWhite = true;
textcontainer.scroller.html = 1;
textcontainer.scroller.htmlText = this.mytext;

It successfully loads the text but won’t scroll. Any ideas where I could start?