Something

if($XHTML_MIME==true)
{
if(!stripos($_SERVER['HTTP_USER_AGENT'],'msie'))
	{
	$CTYPE="application/xhtml+xml";header("Content-type: $CTYPE; charset: $CHARSET");
	}
else
	{
	$CTYPE="text/html";header("Content-type: $CTYPE; charset: $CHARSET");
	}
}
else
{
$CTYPE="text/html";header("Content-type: $CTYPE; charset: $CHARSET");
}