Scrollbar Not working in safari & firefox

Hallo everyone.

im new here and i have a question.

For about 2 weeks now im fighting with the uiscrollbar component in as3.

the swf works well. but when i load the html file the scrollbar doesnt work.

here is my AS.

[COLOR=“Red”]//
function loadTxt4() {

var fileAdres:URLRequest = new URLRequest("Txt/4_txt.txt");

var loader:URLLoader = new URLLoader(fileAdres);

fileAdres.method=URLRequestMethod.POST;
loader.dataFormat=URLLoaderDataFormat.TEXT;

loader.addEventListener(Event.COMPLETE,textLoaded);

}
//
function textLoaded(event:Event):void {

var loader:URLLoader = URLLoader(event.target);

var txt:String = loader.data;

PopUp(getChildByName("popup")).field.htmlText=loader.data;

}[/COLOR]

can someone help me PLEASE!!!
coz im out of ideas of what i coiuld be doing wrong.

it is a dynamic text field with the component on it.

thx in advance