Mine

<?
global $SESS;
$languages = array("nl","en");
$changnl = false;
$changeen = false;
$curln = substr(trim($_SERVER['PHP_SELF']),strlen($_SERVER['PHP_SELF'])-3,3);
if($curln == "/en" || $curln =="/nl"){
	$aln = $curln;
}else{
	$aln = $SESS->userdata['language'];
}
switch ($aln)
{
	case "/en":
		$lang="en";
		$changeen = true;
		break;
	case "english":
		$lang = "en";
		break;
	case "dutch":
		$lang = "nl";
		break;
	case "/nl":
		$lang = "nl";
		$changnl = true;
		break;
	default :
		$lang="nl";
}
if($changeen) {?>{exp:template_language:future language="english"} <?}
if($changnl){
	?>{exp:template_language:future language="dutch"}<? 
	echo $SESS->userdata['language'];
}
?>