PHP: Get name and version of the client

<?php
$agent = getenv("HTTP_USER_AGENT");

echo " You are using $agent.";
?> 

PHP: How to check the client is Miscrosoft Internet Explorer

<?php
$agent = getenv("HTTP_USER_AGENT");
echo($agent);

if (preg_match("/MSIE/i", $agent)) {
     $result = "You are using Microsoft Internet Explorer.";
}else {
     $result = "You are using $agent";
}?>