I'm trying to send a simple data {"DATA1":"111","DATA2":"222"} in json format to PHP from ActionScript 3, 
I saw this codes work for another user, but I don't know why it doesn't work in my system. I'm using XAMPP in local machine.
AS3:
import flash.net.*;
import flash.events.Event;
var request:URLRequest = new URLRequest("http://localhost/as_json_write_2.php")
var variables:URLVariables = new URLVariables()
    variables.DATA1 = "111111"
    variables.DATA2 = "222222"
request.data = variables
request.method = URLRequestMethod.POST
var loader:URLLoader = new URLLoader();
    loader.addEventListener(Event.COMPLETE, handleComplete);
    loader.load(request)
function handleComplete(event:Event) {
    var loader:URLLoader = URLLoader(event.target)
    var vars:URLVariables = new URLVariables(loader.data)
    trace("vars.DATA1: "+vars.DATA1)
    trace("");
    trace("vars.DATA2: "+vars.DATA2)
} 
Animate CC Output:
vars.DATA1: 111111
vars.DATA2: 222222
PHP:
<?php
    $DATA1 = $_POST['DATA1'];
    $DATA2 = $_POST['DATA2'];
    echo "DATA1=".$DATA1;
    echo "&DATA2=".$DATA2;
?>
PHP messages:
Notice: Undefined index: DATA1 in C:\xampp\htdocs\as_json_write_2.php on line 3
Notice: Undefined index: DATA2 in C:\xampp\htdocs\as_json_write_2.php on line 4
DATA1=&DATA2=
 
    