Google, primeira ocorrencia....
http://www.moonlight21.com/class-XMLHttpRequest-php

uma pergunta qual é a classe ?

tenta isso:

<?php
/**
* Class XMLHttpRequest
* XMLHttpRequest emulator using curl.
*
* @author Moises Lima <moises-l@hotmail.com>
* @version 0.5 2007/07/16 23:00:13
* @link http://www.myopera.com/moises-l Comments & suggestions
* @link http://files.myopera.com/moises-l/files/class.XMLHttpRequest.php Available at
* @copyright GPL © 2007, Moises Lima
* @license http://creativecommons.org/licenses/by-nc-sa/2.5/ Released under a Creative Commons License
*/
class XMLHttpRequest{
/**
* String version of data returned from server process.
* @link http://www.w3.org/TR/XMLHttpRequest/#dfn-responsetext
* @access public
* @var string
* @name $responseText
*/
var $responseText;
/**
* DOM-compatible document object of data returned from server process.
* which can be examined and parsed using W3C DOM node tree methods and properties
* @link http://www.w3.org/TR/XMLHttpRequest/#dfn-responsexml
* @access public
* @var object
* @name $responseXML
*/
var $responseXML;
/**
* The http status code returned by server as a number (e.g. 404 for "Not Found" or 200 for "OK").
* @link http://www.w3.org/TR/XMLHttpRequest/#dfn-status
* @access public
* @var number
* @name $status
*/
var $status;
/**
* The http status code returned by server as a string (e.g. "Not Found" or "OK")
* @link http://www.w3.org/TR/XMLHttpRequest/#dfn-statustext
* @access public
* @var string
* @name $statusText
*/
var $statusText;
/**
* The state of the object
* 0 = uninitialized
* 1 = loading
* 2 = loaded
* 3 = interactive
* 4 = complete
* @link http://www.w3.org/TR/XMLHttpRequest/#dfn-readystate
* @access public
* @var number
* @name $readyState
*/
var $readyState;
/**
* The error string
* @link http://www.w3.org/TR/XMLHttpRequest/#notcovered
* @access public
* @var string
* @name $error
*/
var $error;
/**
* An event handler for an event that fires at every state change
* @link http://www.w3.org/TR/XMLHttpRequest/#dfn-onreadystatechange
* @access public
* @name $onreadystatechange
*/
var $onreadystatechange;
/**
* An event handler for an event that fires at finished requisition
* @link http://www.w3.org/TR/XMLHttpRequest/#notcovered
* @access public
* @name $onload
*/
var $onload;
/**
* An event handler for an event that fires at errors
* @link http://www.w3.org/TR/XMLHttpRequest/#notcovered
* @access public
* @name $onerror
*/
var $onerror; // http://www.w3.org/TR/XMLHttpRequest/#notcovered
/**
* cURL handle
* @access private
* @name $curl
*/
var $curl;
/**
* responseHeaders process
* @access private
* @name $responseHeaders
*/
var $responseHeaders;
/**
* cURL headers
* @access private
* @name $headers
*/
var $headers=array("Connection: Keep-Alive","Keep-Alive: 300");
/**
* Curl info
* @access public
* @name $curl_version
* @var Array
*/
var $curl_version;
/**
* TRUE to follow any "Location: " header that the server sends as part of the HTTP header.
* @access public
* @name $followLocation
* @var Bolean
*/
var $followLocation;

/**
* Class constructor (compatibility with PHP 4).
*/
function XMLHttpRequest(){
$this->open="function open() { [native code] }";
$this->setRequestHeader="function setRequestHeader() { [native code] }";
$this->getAllResponseHeaders="function getAllResponseHeaders() { [native code] }";
$this->getResponseHeader="function getResponseHeader() { [native code] }";
$this->send="function send() { [native code] }";
$this->readyState = 0;
$this->curl = curl_init();
$this->curl_version = curl_version();
$this->followLocation=false;
curl_setopt($this->curl, CURLOPT_HEADER, true);
if(isset($_SERVER['HTTP_USER_AGENT'])){
curl_setopt($this->curl, CURLOPT_USERAGENT, $_SERVER['HTTP_USER_AGENT'] );
}else{
curl_setopt($this->curl, CURLOPT_USERAGENT, "XMLHttpRequest/0.2");
}
curl_setopt($this->curl, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($this->curl, CURLOPT_TIMEOUT, 1000);
curl_setopt($this->curl, CURLOPT_CONNECTTIMEOUT, 300);
}
/**
* @access private
*/
function __toString(){
return "[object XMLHttpRequest]";
}
/**
* Specifies the method, URL, and other optional attributes of a request.
* @access public
* @link http://www.w3.org/TR/XMLHttpRequest/#dfn-open
* @param String $method HTTP Methods defined in section 5.1.1 of RFC 2616 http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html
* @param String $url Specifies either the absolute or a relative URL of the data on the Web service.
* @param Bolean $async FakeSauro Erectus.
* @param String $user specifies the name of the user for HTTP authentication.
* @param String $password specifies the password of the user for HTTP authentication.
* @return void
*/
function open($method, $url, $async=true, $user="", $password=""){
$this->readyState = 1;
if(!empty($method) && !empty($url)){
$method=strtoupper(trim($method));
/*
if(!ereg("^(GET|POST|HEAD|PUT|DELETE|OPTIONS)$",$method)){
throw new Exception("Unknown HTTP request method [$method]");
}
*/
if(isset($_SERVER['HTTP_REFERER']) && empty($this->url) ){
curl_setopt($this->curl, CURLOPT_REFERER, $_SERVER['HTTP_REFERER']);
}elseif(isset($this->url)){
curl_setopt($this->curl, CURLOPT_REFERER, $this->url);
}
$this->url = $url;
curl_setopt($this->curl, CURLOPT_URL, $this->url);
if($method=="POST"){
curl_setopt($this->curl, CURLOPT_POST, 1);
}elseif($method=="GET"){
curl_setopt($this->curl, CURLOPT_POST, 0);
}else{
curl_setopt($this->curl, CURLOPT_POST, 0);
curl_setopt($this->curl, CURLOPT_CUSTOMREQUEST, $method);
}
}
if(ereg("^(https)",$url)){
curl_setopt($this->curl,CURLOPT_SSL_VERIFYPEER,false);
}
if(!empty($user) && !empty($password)){
curl_setopt($this->curl, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
curl_setopt($this->curl,CURLOPT_USERPWD,$user.":". $password);
}
}
/**
* Assigns a label/value pair to the header to be sent with a request.
* @access public
* @link http://www.w3.org/TR/XMLHttpRequest/#dfn-setrequestheader
* @param String $label Specifies the header label.
* @param String $value Specifies the header value.
* @return void
*/
function setRequestHeader($label, $value){
$this->headers[] = "$label: $value";
curl_setopt($this->curl, CURLOPT_HTTPHEADER, $this->headers);
}
/**
* Returns complete set of headers (labels and values) as a string.
* @access public
* @link http://www.w3.org/TR/XMLHttpRequest/#dfn-getallresponseheaders
* @return string Complete set of headers (labels and values) as a string
*/
function getAllResponseHeaders(){
return $this->responseHeaders;
}
/**
* Returns the value of the specified http header.
* @access public
* @link http://www.w3.org/TR/XMLHttpRequest/#dfn-getresponseheader.
* @param String $label
* @return String|null The string value of a single header label.
*/
function getResponseHeader($label){
$value=array();
preg_match_all('/(?s)'.$label.': (.*?)\s\n/i', $this->responseHeaders , $value);
if(count($value ) > 0){
return implode(', ' , $value[1]);
}
return null;
}

function getResponseHeader2($label){
$value=array();
preg_match('/(?s)'.$label.': (.*?)\s\n/i', $this->responseHeaders , $value);
if(count($value ) > 0){
return $value[1];
}
return null;
}
/**
* Transmits the request, optionally with postable string or DOM object data.
* @access public
* @link http://www.w3.org/TR/XMLHttpRequest/#dfn-getresponseheader
* @param String $data
* @return void
*/
function send($data=null){
$sT=array();
if(isset($this->onreadystatechange))eval($this->onreadystatechange);
if($data){
curl_setopt($this->curl, CURLOPT_POSTFIELDS, $data);
}
$this->response= curl_exec($this->curl);
$header_size = curl_getinfo($this->curl, CURLINFO_HEADER_SIZE);
$this->responseHeaders = substr($this->response, 0, $header_size - 4);
if($this->followLocation){
$location=array();
while(preg_match('/Location:(.*?)\n/', $this->responseHeaders, $location)){
curl_setopt($this->curl, CURLOPT_REFERER, $this->url);
$url = @parse_url(trim(array_pop($location)));
if (!$url){
break;
}
$last_url = parse_url(curl_getinfo($this->curl, CURLINFO_EFFECTIVE_URL));
if (!isset($url['scheme']))$url['scheme'] = $last_url['scheme'];
if (!isset($url['host']))$url['host'] = $last_url['host'];
if (!isset($url['path']))$url['path'] = $last_url['path'];
$this->url = $url['scheme'] . '://' . $url['host'] . $url['path'] . (isset($url['query'])?'?'.$url['query']:'');
curl_setopt($this->curl, CURLOPT_POST, 0);
//curl_setopt($this->curl, CURLOPT_POSTFIELDS,0);
curl_setopt($this->curl, CURLOPT_URL, $this->url);
$this->response= curl_exec($this->curl);
$header_size = curl_getinfo($this->curl, CURLINFO_HEADER_SIZE);
$this->responseHeaders = substr($this->response, 0, $header_size - 4);
}
}
$this->error = curl_error($this->curl);
if ($this->error) {
if(isset($this->onerror))eval($this->onerror);
}
$this->readyState = 2;
if(isset($this->onreadystatechange))eval($this->onreadystatechange);
$this->responseText = substr($this->response, $header_size);
preg_match('/^HTTP\/\d\.\d\s+(\d{3}) (.*)\s\n/i', $this->responseHeaders , $sT);
if(count($sT ) > 2){
$this->responseHeaders = ereg_replace ($sT[0], "", $this->responseHeaders);
$this->status = $sT[1];
$this->statusText = $sT[2];
}
if(version_compare(PHP_VERSION , "5", ">=")){
if (preg_match('/(application|text)\/[\w+\+]?xml/i', $this->getResponseHeader("Content-Type"))){
libxml_use_internal_errors(true);
$this->responseXML = new DOMDocument();
$this->responseXML->loadXML($this->responseText);
$errors = libxml_get_errors();
if (!empty($errors)){
$this->responseXML=null;
$error=$errors[0];
$this->error= trim($error->message) ." in $this->url on line $error->line column: $error->column <br />";
if(isset($this->onerror))eval($this->onerror);
}
libxml_clear_errors();
}
}
$this->readyState = 3;
if(isset($this->onreadystatechange))eval($this->onreadystatechange);
$this->headers=Array();
$this->readyState = 4;
if(isset($this->onreadystatechange))eval($this->onreadystatechange);
if(isset($this->onload))eval($this->onload);
}
/**
* Closes a cURL session and frees all resources.
* @name close
* @access public
* @return void
*/
function close(){
curl_close($this->curl);
}
}
?>