<?
$xhtml = (preg_match('|\bapplication/xhtml\+xml\b|', $_SERVER['HTTP_ACCEPT']) ? true : false);
header('Content-Type: '
	. ($xhtml
		? 'application/xhtml+xml'
		: 'text/html')
	. '; charset=UTF-8');
if ($xhtml)
	echo '<?xml version="1.0" encoding="UTF-8"?>' . "\n";
?>