Dynamic Text Alignment

Hello everybody.... well my question is ... How I can align a dynamic text loading xml file?

My code on Actionscript and XML is :

XML code:

It load the halls with text only....

<halls>
    <hall>Congress A </hall>
    <hall>Congress B</hall>
    <hall>Congress C</hall>
    <hall></hall>
    <hall></hall>
    <hall></hall>
    <hall></hall>
    <hall></hall>
    <hall></hall>
    <hall></hall>               
</halls>

AS code:

var urlLDR:URLLoader=new URLLoader();

urlLDR.addEventListener(Event.COMPLETE,f);

urlLDR.load(new URLRequest("hallsXML.xml"));

function f(e:Event) {

    var xml:XML =new XML(urlLDR.data);

    TXTvHall.text = "";

    for(var i:uint=0;i<xml.hall.length();i++){

        TXTvHall.appendText(xml.hall+"\n");

    }

}

The result of my flash is the next  in the dynamic text... so as you can see it doesnt appear aligned in the center..

How can I do that?