URL geeft geen ID weer bij ID _GET

<?php
require_once("inc/connection.php");
mysql_select_db("nieuws");

$id = $_GET["id"];
$datum = $_POST["datum"];
$titel = $_POST["titel"];
$artikel = $_POST["artikel"];
?>
<script type="text/javascript">
$(document).ready(function(){
	
//Set default open/close settings
$('.acc_containernieuws').hide(); //Hide/close all containers
/*$('.acc_trigger:first').addClass('active').next().show(); //Add "active" class to first trigger, then show/open the immediate next container*/

//On Click
$('.acc_triggernieuws').click(function(){
	if( $(this).next().is(':hidden') ) { //If immediate next container is closed...
		$('.acc_triggernieuws').removeClass('active').next().slideUp(); //Remove all .acc_trigger classes and slide up the immediate next container
		$(this).toggleClass('active').next().slideDown(); //Add .acc_trigger class to clicked trigger and slide down the immediate next container
	}
	return false; //Prevent the browser jump to the link anchor
});

});
</script>
<?php
		$id=mysql_real_escape_string($_GET['id']);
		$query="SELECT id,datum,titel,artikel FROM nieuws ORDER BY id DESC";
		$result = mysql_query($query);
		while(list($id,$datum,$titel,$artikel) = mysql_fetch_row($result)){
		echo("<div id=\"artikeltitel\" align=\"center\">
			<div id=\"containerdatum\">$datum</div>
			<div id=\"containertitel\">$titel</div>
			<div id=\"container3\" style=\"font-size:12px;\"></div>
		</div>
<div class=\"containernieuws\" align=\"center\">
		<h2 class=\"acc_triggernieuws\"><a href=\"#\"> &#187; </a></h2>
	<div class=\"acc_containernieuws\">
	<div class=\"blocknieuws\">$artikel</div>
	</div>
</div>
");
		}
		?>