AJAX + PHP = Not Updating MySQL DB ... code inside

The JAVASCRIPT I'm using:

<script type="text/javascript">

  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;
  }


	function rating(val){
		ratequest=GetXmlHttpObject();
		if (ratequest==null){
		  alert ("Your browser does not support AJAX!");
		  return;
		  }
		var url="rate_time.php";
		url=url+"?id=" + val;
    url=url+"&sid="+Math.random();
		ratequest.open("GET",url,true);
		ratequest.onreadystatechange = handleRequestStateChange;
		ratequest.send(null);
	}

</script>

Code (markup):

As you can see it calls a .php file called rate_time.php ... and that file is:

<?php
session_start();
include_once("db.php");
$id=mysql_real_escape_string($_GET['id']);
mysql_query("INSERT INTO log SET rating='1', book_id='$id'");
?>

Code (markup):

db.php connects to the database.

I'm using the following HTML to call it:

<a href="#" onClick="rating(23)">1</a>

Code (markup):

However the issue is that I cannot get the script to insert the rating into the MySQL DB.

I can run the rate_time.php file via the browser and it inserts everything, but just not via JS/AJAX.

Anyone see any errors in the coding?

 

hehehe use Jquery or some other javascript framework
with jquery is only:

function rating(val) {
$.get('rate_time.php?id='+val);
}