Can someone check this As3 please?

Hi, Ive made this contact form in cs5 as3 from a tutorial. It sends fine but I don't get the sent success or failed message. It says "sending" but the form stays filled in and I don't get the successful message. Here is the as3. I hope someone can help me here!

Thanks...

import fl.managers.StyleManager;
import flash.events.Event;

email_txt.addEventListener(Event.CHANGE, textChanged);

function textChanged(evt:Event):void {
var typed:String = evt.target.text.slice(evt.target.text.length-1, evt.target.text.length);
if (typed == "\"") {
evt.target.text = evt.target.text.slice(0, evt.target.text.length-1)+"@";
}
}

StyleManager.setStyle("textFormat", new TextFormat("Verdana", 11, 0x000000));
const SENDING:String = "Sending";
const SENT_SUCCESS:String = "Successful";
const SENT_FAILED:String = "Unsuccessful";
var tmr:Timer;

function resetTextFields():void {
name_txt.text = "";
email_txt.text = "";
message_txt.text = "";
}

function resetContactForm():void {
submit_btn.enabled = true;
feedback_mc.visible = false;
clearErrors();
}

function afterTmrWait(evt:TimerEvent):void {
tmr.stop();
tmr.removeEventListener(TimerEvent.TIMER, afterTmrWait);
resetContactForm();
}

// From AS3 Doc.
function validateEmail(str:String):Boolean {
var pattern:RegExp = /(\w|[_.\-])+@((\w|-)+\.)+\w{2,4}+/;
var result:Object = pattern.exec(str);
if(result == null) {
return false;
}
return true;
}

function submitForm(evt:MouseEvent):void {

clearErrors();

var passChecks:Boolean = true;

if(name_txt.text.length < 1) {
nameError_mc.visible = true;
passChecks = false;
}
if(!validateEmail(email_txt.text)) {
emailError_mc.visible = true;
passChecks = false;
}
if(message_txt.text.length < 1) {
messageError_mc.visible = true;
passChecks = false;
}

if(passChecks) {
submit_btn.enabled = false;
feedback_mc.visible = true;
feedback_mc.gotoAndStop(SENDING);

var urlVars:URLVariables = new URLVariables();
var urlReq:URLRequest = new URLRequest("send_email.php");
var ldr:URLLoader = new URLLoader();

urlVars.name = name_txt.text;
urlVars.email = email_txt.text;
urlVars.message = message_txt.text;
urlReq.data = urlVars;
urlReq.method = URLRequestMethod.POST;
ldr.addEventListener(Event.COMPLETE, serverFeedback);
ldr.load(urlReq);
}
}

function serverFeedback(evt:Event):void {
var ldr:URLLoader = evt.target as URLLoader;
var urlVars:URLVariables = new URLVariables(ldr.data);

if(urlVars.result == SENT_SUCCESS) {
feedback_mc.gotoAndStop(SENT_SUCCESS);
resetTextFields();
} else if(urlVars.result == SENT_FAILED) {
feedback_mc.gotoAndStop(SENT_FAILED);
}

tmr = new Timer(3000, 1);
tmr.addEventListener(TimerEvent.TIMER, afterTmrWait);
tmr.start();
}

function clearErrors():void {
nameError_mc.visible = false;
emailError_mc.visible = false;
messageError_mc.visible = false;
}

submit_btn.addEventListener(MouseEvent.CLICK, submitForm);

resetTextFields();
resetContactForm();