Textfield Formating Problems Action script 3

Question

Apologies for a probably very basic question, but I am very
new to flash and working alone.
I am trying to write a script which reads text from a file
and display it in the movie. It all works fine but I can not get
the
TextFormat object to do anything at all.
function completeHandler(event:Event):void {
var loader:URLLoader = URLLoader(event.target);
var thistext = loader.data;
var my_fmt:TextFormat = new TextFormat();
my_fmt.bold = true;
my_fmt.font = "Courier";
my_fmt.size = 40;
trace(thistext);
tField = new TextField();
tField.autoSize = "left";
tField.background = false;
tField.border = false;
tField.x = 10;
tField.y = 500;
tField.alpha = 50
tField.setTextFormat(my_fmt);
tField.backgroundColor = 0x23169C;
tField.textColor = 0xFF0000;
tField.text = thistext;
addChild(tField);
Most of the TextField properties work except the ALPHA, which
I really need to set for my application.
None of the TextFormat properties including font, bold etc
are being applied. What have I failed to do?
Thanks

Answer 1

OK got the text working with a little fiddling
package {
import flash.display.*;
import flash.text.*;
public class testas3 extends Sprite {
function testas3(){
var thistext = "Some test text";
var tField:TextField = new TextField();
tField.autoSize = "left";
tField.background = false;
tField.border = false;
tField.x = 10;
tField.y = 50;
tField.alpha = 50
tField.backgroundColor = 0x23169C;
tField.textColor = 0x000000;
var my_fmt:TextFormat = new TextFormat();
my_fmt.bold = true;
my_fmt.font = "Times New Roman";
my_fmt.size = 40;
//my_fmt.underline = true;
trace(thistext);
tField.text = thistext;
// tField.defaultTextFormat= my_fmt; not like this but like
next line
tField.setTextFormat(my_fmt);
addChild(tField);
Just in case anyone else is struggling with this