<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Test</title>
<script type="text/javascript" src="jquery-2.1.4.js"></script>
<script type="text/javascript">
$(document).ready(function(){
    var request = $.ajax({
        url: "result.php",
        type: "POST",
        data: {id: "testvalue"},
        dataType: "html"
    });

    request.done(function(msg) {
        $("#jsbox").html(msg);
    });

    request.fail(function(jqXHR, textStatus){
        $("#jsbox").html("Request failed: " + textStatus);
    });
});
</script>
</head>
<body>
<div id="jsbox"></div>
</body>
</html>

<?php
if(isset($_REQUEST["id"])){
    echo $_REQUEST["id"];
}
?>