Код:
<?php
$filename = 'test.txt';
$somecontent = "Add this to the file\n";
$xmlfromflash = $_POST['xml'];
А во flash:
Код:
var request:URLRequest = new URLRequest(url);
var vars:URLVariables=new URLVariables();
vars.xml="<root>test<root>";
request.data=vars;
...