Blog Roll problem

programming flash
1

I am trying to make a blog roll program that will put the titles of a client’s blog on their homepage. i ran through a tutorial that got most of it working, but when i went to move from the tutorial to the client’s program, i started running into some errors. since i have no idea what they mean, i can’t even begin to figure out what is causing them.

TypeError: Error #1034: Type Coercion failed: cannot convert fl.text::TLFTextField@320a80e1 to flash.text.TextField.
at fl.motion::AnimatorBase/play()
at fl.motion::AnimatorBase$/processCurrentFrame()
at fl.motion::AnimatorFactoryBase/addTargetInfo()
at RSS_Reader_fla::MainTimeline()
TypeError: Error #1009: Cannot access a property or method of a null object reference.
at RSS_Reader_fla::MainTimeline/frame1()
TypeError: Error #1009: Cannot access a property or method of a null object reference.
at RSS_Reader_fla::MainTimeline/displayPost()
at RSS_Reader_fla::MainTimeline/onXMLFileLoaded()
at flash.events::EventDispatcher/dispatchEventFunction()
at flash.events::EventDispatcher/dispatchEvent()
at flash.net::URLLoader/onComplete()

and here is my code

import flash.events.IOErrorEvent;
import flash.net.URLLoader;
import flash.net.URLRequest;
import flash.events.Event;
import flash.events.MouseEvent;
import flash.text.TextField;
import flash.text.TextFieldAutoSize;
import flash.text.TextFormat;

var channelTitle_txt:TextField;
var blogRoll_txt:TextField;

var urlLoader:URLLoader = new URLLoader();
urlLoader.load(new URLRequest("http://www.permadi.com/blog/rss2/"));
urlLoader.addEventListener(Event.COMPLETE, onXMLFileLoaded);
urlLoader.addEventListener(IOErrorEvent.IO_ERROR, onIOError);
blogRoll_txt.text = "Loading";
stop();

var numberOfPosts:int = 0;
var currentPost:int = 0;
var myXML:XML = null;

/**
*Called when the XML data has been loaded
**/
function onXMLFileLoaded(e:Event):void
{
    myXML = new XML(e.target.data);
    //description.text = String(myXML.toXMLString());
    currentPost = 0;
    numberOfPosts = myXML.channel.item.length();
    displayPost();
}

/**
*Display Blog Roll.
**/
function displayPost():void
{
    channelTitle_txt.text = myXML.channel.title;
    for(var i:Number=0; i<=numberOfPosts; i++)
    {
        blogRoll_txt.appendText(myXML.channel.item*.title + "
");
    }
}

/**
*Helps diagnose problem when the loader faild to load the XML data.
**/
function onIOError(e:IOErrorEvent):void
{
    trace(e.toString());
    blogRoll_txt.text = e.toString();
}