AJAX和GET []困境

Question

我通过创建导致include（）文件的GET VARS在我的页面上使用PHP模板。我在博客页面上有一个评论系统，它在提交时发送一个AJAX GET请求。但是，当用户单击提交时，所有变量都会转到url，我的php模板脚本无法识别它，为了安全起见，只需重定向回主页。我该如何避免这种情况？

AJAX代码：

<script>
        function postComment() {
            if (window.XMLHttpRequest) {// code for IE7+, Firefox, Chrome, Opera, Safari
                xmlhttp = new XMLHttpRequest();
            }


            else {// code for IE6, IE5

                xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
            }
            xmlhttp.onreadystatechange = function () {
                if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
                    document.getElementById("commentHint").innerHTML = xmlhttp.responseText;
                }
            }
            var comment = document.getElementById("commenter").value;
            var id = document.getElementById("postID").value;
            xmlhttp.open("GET", "commentpost.php?comment=" + comment + "&postID=" + id, true);
            xmlhttp.send();

        }
        setTimeout("postComment()", 1000);

    </script>
    <form>
        <div id="comment">
            <textarea name="comment" id="commenter" rows="4" cols="125" style="max-width: 950px; max-height: 140px;" placeholder="<?php echo $_SESSION["name"] ?>, Write Your Comment Here" class="form-control"></textarea><br>
            <div id="commentHint"></div>
            <input type="submit" onclick="postComment()" value="Submit Comment"  class="btn btn-success btn-sm ">
            <input type="hidden" value="<?php echo $post_id ?>" id="postID">

        </div>
    </form>

模板代码：

               $p = $_GET["page"];
                if (preg_match("</^[a-zA-Z ]*$/>", $p)) {
                    session_start();
                    session_destroy();
                    header("location: index.php?error=2");
                } else {

                    switch ($p) {
                        case "2";
                            include("about.php");
                            break;
                        case "3";
                            include("games.php"); //CREATE PAGES
                            break;
                        case "4";
                            include("blog.php"); <== THIS PAGE IS THE BLOG PAGE
                            break;
                        case "5";
                            include("info.php");
                            break;
                        case "6";
                            include("settings.php");
                            break;
                        case "7";
                            include("functiontest.php");
                            break;
                        case "8";
                            include("styletech.php");
                            break;
                        case "9";
                            include("userlist.php");
                            break;
                        case "10";
                            include("adminpanel.php");
                            break;
                        case "11";
                            include("StyleTuts/styletech.php");
                            break;
                        default:
                            include("home.php");
                            break;
                    }
                }