$url = "http://siteadi.com/dosya.asmx/alan";
$body = "xx=XXX&BB=bbb";
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HTTPHEADER, array("Content-Type: application/x-www-form-urlencoded"));
curl_setopt($ch, CURLOPT_POSTFIELDS, $body);
curl_setopt($ch, CURLOPT_POST, 1);  
$result = curl_exec ($ch);
curl_close ($ch);
if(!empty($result))
	$result = simplexml_load_string($result, 'SimpleXMLElement', LIBXML_NOCDATA);


print_r($result);