Movieclip's width is always zero

Question

Hi, I am having some trouble with some Movieclip this time so I come here to ask for help again.  Please see following for my current code, whenever I try detecting the MC's width, it always display zero for some reason.
On the 2nd frame, the following function will start loading.  After the initial turn, I have another condition statement to check whether it should go to another frame or not.  If it's staying in this frame, it will load this function again, and the temp_counter will increases.
tel_phrase_holder is just a dynamic textfield I use to display the width only.
function tel_load () {
    tel_holder.removeChildAt(0);
    var a = new Loader();   
    tel_holder.addChild(a);
    a.load(new URLRequest(tel_pic_start[temp_counter - 1]));
    tel_phrase_holder.text = tel_holder.width.toString();
I tried putting "tel_phrase_holder.text = tel_holder.width.toString();" at the beginning as well like I did at the following code.  It's slightly better, but it's loading the previous picture's width instead of the current picture's width.
function tel_load () {
   tel_phrase_holder.text = tel_holder.width.toString();
     tel_holder.removeChildAt(0);
     var a = new Loader();   
     tel_holder.addChild(a);
     a.load(new URLRequest(tel_pic_start[temp_counter - 1]));
Thanks in advance

Answer 1

When you issue a URLRequest for the loader you have to wait until the content finishes loading and is ready to be accessed before you try and get properties. That is why when you put the code at the beginning you get the results of the "previous" contents, because at that point they aren't previous at all!
Check out the documentation for the Loader class. Basically you need to do this:
var a:Loader = new Loader();
a.contentLoaderInfo.addEventListener(Event.INIT,initHandler)
function initHandler(e:Event){
     // the content has loaded and is ready
     trace(e.target);
     // do what you need