Mine

<?
	$html = false;
	$wml = false;
	
	$server_accept = $_SERVER['HTTP_ACCEPT'];
	
	$accept_html = eregi("application/xhtml",$server_accept);
	if($accept_html !=1){
		$accept_html = eregi("text/html",$server_accept);
	}
	
	if($accept_html==1){
		$html = true;
		$wml = false;
	}else{
		$html = false;
		$wml = true;
	}
	if($html == true){
		include "html.php";
	}
	
	if($wml== true){
		header("Content-type: text/vnd.wap.wml");
		include "wml.php";
	}
?>