jQuery的：

$.post('url_to_script',{"anyData": "that is needed"}, function(data){
    $('#headertarget').text('data');
});

PHP：

$anyData = $_POST['anyData'];
function getAnswer ($inp){
    //logic goes here
    return "a string of some sort";
}
echo getAnswer($anyData);
exit;

这将让你发送回客户端进入标题元素的文字。

It will put any text you send back to the client into the heading element.