<"POST".$url."HTTP/1.0",
    "Content-type: text/xml; charset=\"gb2312\"",
    "Accept: text/xml",
    "Content-length: ".strlen($postvar)
  );
  curl_setopt($ch, CURLOPT_URL, $url);
  curl_setopt($ch, CURLOPT_RETURNTRANSFER,1);
  curl_setopt($ch, CURLOPT_POST, 1);
  curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
  curl_setopt($ch, CURLOPT_POSTFIELDS, $postvar);
  $res = curl_exec ($ch);
  curl_close ($ch);
  return $res;
}

$baiduXML = "<"1.0\" encoding=\"gb2312\"";

$res = postUrl('http://ping.baidu.com/ping/RPC2', $baiduXML);

if ( strpos($res, "<int>0</int>") )
{
  echo "PING成功";
}else{
  echo "PING失败";
}

?>