Here I wrote this the other day for IE Mac 5..
if(preg_match("/MSIE/",$HTTP_USER_AGENT))
{
$Browser_Name="MSIE";
}
if (preg_match("/5.0/", $HTTP_USER_AGENT)) {
$Browser_Version ="5";
}
if(preg_match("/Mac/",$HTTP_USER_AGENT))
{
$Browser_Platform="Macintosh";
}else{
$Browser_Platform="Windows";
}
if (($Browser_Platform == "Macintosh") && ($Browser_Version == "5") && ($Browser_Name == "MSIE")) {
echo " Whatever you want";
}
Mind you preg match is a php4 version..
Ray