Insert query problem

Question

I have a insert query that I have not changed, but for some reason it will not insert anything into the database.
The data gets inserted by a Ajax submit form and goes to insert.php
if(isset($_POST['message_wall'])){
    /* Connection to Database */
    include('config.php');
    /* Remove HTML tag to prevent query injection */
    $message = mysql_real_escape_string($_POST['message_wall']);
    $to = mysql_real_escape_string($_POST['profile_to']);
    $sql    =    'INSERT INTO wall (message) VALUES(
                "'.$message.'")';
                 mysql_query($sql);
I want to be able to add a user_id into the database too
The ajax code:
$(document).ready(function(){
    $("form#submit_wall").submit(function() {
    var message_wall = $('#message_wall').attr('value');
        $.ajax({
            type: "POST",
            url: "insert.php",
            data: "message_wall="+ message_wall,
            success: function(){
                $("ul#wall").prepend("<li style='display:none'>"+message_wall+"</li><br><hr>");
                $("ul#wall li:first").fadeIn();
    return false;

Answer 1

hi,
while I was waiting for your message I went back to the raw code.
I changed my code and now it works but it falls again once I add the other info in hidden fields
        $.ajax({
            type: "POST",
            url: "insert.php",
            data: "message_wall="+ message_wall,
            date: "msg_date="+ msg_date,
            success: function(){
                $("ul#wall").prepend("<li style='display:none'>"+message_wall+"</li><br />"+msg_date+"<hr />");
                $("ul#wall li:first").fadeIn();
<form action="" id="submit_wall" name="submit_wall">
<textarea name="name" id="message_wall" cols="70" rows="2" onclick="make_blank();"></textarea>
<div align="left"><button type="submit">Post to wall</button></div>
<input name="profile_to" type="hidden" value="<?php echo $row_user_profile['user_id']; ?>" />
<input name="msg_date" type="hidden" value="<?php echo date("d/m/y");?>" />
</form>
how do I add more than one post option?
Is this right:
            data: "message_wall="+ message_wall,
             date: "msg_date="+ msg_date,
I tried
            data: "message_wall="+ message_wall, "msg_date="+ msg_date,
But nothing. I take it this is where the fields are sent