Hi guys, any ideas why this would update in FF but not in IE?

The code i have is:

index.php
Code:
<html>

<head>

<title>B-rad's Wall</title>

<meta http-equiv="pragma" content="no-cache" />
<meta http-equiv="cache-control" content="no-cache" />
<link rel="stylesheet" type="text/css" href="css.css" />
<script type="text/javascript" src="jquery/jquery-1.3.2.min.js"></script>

<script type="text/javascript">
$(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>");
				$("ul#wall li:first").fadeIn();
			}
		});
	return false;
	});
});
</script>

</head>


<body>
<h2>B-rad's Wall</h2>
<form action="" id="submit_wall">

<label for="message_wall">Your message:&nbsp;</label>

<input type="text" id="message_wall" class="input" value="Message - First Name" />
<button type="submit">Write!</button>

<button type="reset" onclick="window.location='http://202.45.110.174/social/test'">Refresh</button>

</form>

<table align="center" border="0" height="100%" width="100%">
<tr>
<td width="32%">

</td>
<td  width="53%">

<script type="text/javascript">
var xmlhttp;

function stateChanged()
{
if (xmlhttp.readyState==4)
{
document.getElementById("_ticker").innerHTML=xmlhttp.responseText;
}
}

function GetXmlHttpObject()
{
if (window.XMLHttpRequest)
  {
  // code for IE7+, Firefox, Chrome, Opera, Safari
  return new XMLHttpRequest();
  }
if (window.ActiveXObject)
  {
  // code for IE6, IE5
  return new ActiveXObject("Microsoft.XMLHTTP");
  }
return null;
}


  var init_ticker = function(){

   xmlhttp=GetXmlHttpObject();
if (xmlhttp==null)
  {
  alert ("Browser does not support HTTP Request");
  return;
  }
var url="data.php";
xmlhttp.onreadystatechange=stateChanged;
xmlhttp.open("GET",url,true);
xmlhttp.send(null);
xmlhttp.timeout = 10000
  };
  setInterval(init_ticker, 1000);
  window.onload = init_ticker;



</script>
<div class="_ticker" id="_ticker">Loading...</div>
</td>
<td width="15%">&nbsp;</td>
</tr> 
</table> 
<br />
<br />
<a href="http://www.redhost.com.au"><img src="redhost.jpg" align="center" border="0" /></a>
<h4>Affordable Web Hosting and Design</h4>
<h4>Email: Brad@redhost.com.au  .:. <a href="http://www.redhost.com.au">www.Redhost.com.au</a></h4>



</body>

</html>
data.php
Code:
<?
$db_host="localhost";

$db_name="messages";

$username="username";

$password="*******";

$db_con=mysql_connect($db_host,$username,$password);

$connection_string=mysql_select_db($db_name);

mysql_connect($db_host,$username,$password);

mysql_select_db($db_name);


$result = mysql_query("select * from messages ORDER BY ID desc");
if(!$result) echo mysql_error();
else {
while($row = mysql_fetch_row($result)) {
?>
<ul id="wall">
<li>
<?
echo "$row[1]<br />\n";
?>
</li>
</ul>
<?
}
}
?>
and the two javascripts up in the index.php page use this to insert the message into the database

insert.php
Code:
<?php
if(isset($_POST['message_wall'])){
/* Connection to Database */
include('config.php');
/* Remove HTML tag to prevent query injection */
$message = strip_tags($_POST['message_wall']);

$sql = 'INSERT INTO messages (messages) VALUES( "'.$message.'")';
mysql_query($sql);

echo $message;


} else { echo '0'; }
?>
It all works fine if i take the Ajax out and chuck in some php to grab the messages but i want it to auto update...

This has got me stumped... Site with Ajax is at http://202.45.110.174/social/test