Does somebody know a simple browsercheck in php or is it more likely to use a javascript???
Try HTTP_USER_AGENT it will return the browser and some other info as well.
PHP gathers tons of data like this in it's HTTP*VARS.
Try print_r($HTTP_SERVER_VARS); and do the same for the others, see what you get.
http://www.php.net/manual/en/language.variables.predefined.php#language.variables.predefined.php
A better way to view all the variables available is to enter
<?
phpinfo();
?>
it will give a list of all variables and settings for your server.
Which doesn't list the GET, POST or COOKIE vars, but that's not really relevant here.