跪求ajax有关问题

	include "MessageServer.class.php";
	@header( 'Content-Type:text/xml;charset=utf-8'); 
	@header("Cache-Control: no-cache");
	$getter = $_POST['getter'];
	$sender = $_POST['sender'];

	//调用MessageSerive获取信息
	$messageServer = new MessageServer();

	$messList = $messageServer->getMessage($getter, $sender);

	echo $messList;
	
?>