Tjek af browser+version m. PHP

<?php
function browser_info($agent=null) {
  // Declare known browsers to look for
  $known = array('msie', 'firefox', 'safari', 'webkit', 'opera', 'netscape',
    'konqueror', 'gecko');

  // Clean up agent and build regex that matches phrases for known browsers
  // (e.g. "Firefox/2.0" or "MSIE 6.0" (This only matches the major and minor
  // version numbers.  E.g. "2.0.0.6" is parsed as simply "2.0"
  $agent = strtolower($agent ? $agent : $_SERVER['HTTP_USER_AGENT']);
  $pattern = '#(?<browser>' . join('|', $known) .
    ')[/ ]+(?<version>[0-9]+(?:\.[0-9]+)?)#';

  // Find all phrases (or return empty array if none found)
  if (!preg_match_all($pattern, $agent, $matches)) return array();

  // Since some UAs have more than one phrase (e.g Firefox has a Gecko phrase,
  // Opera 7,8 have a MSIE phrase), use the last one found (the right-most one
  // in the UA).  That's usually the most correct.
  $i = count($matches['browser'])-1;
  return array($matches['browser'][$i] => $matches['version'][$i]);
}

$ua = browser_info();
print_r($ua);
?>

<?php
class Browser
{
    private $props    = array("Version" => "0.0.0",
                                "Name" => "unknown",
                                "Agent" => "unknown") ;

    public function __Construct()
    {
        $browsers = array("firefox", "msie", "opera", "chrome", "safari",
                            "mozilla", "seamonkey",    "konqueror", "netscape",
                            "gecko", "navigator", "mosaic", "lynx", "amaya",
                            "omniweb", "avant", "camino", "flock", "aol");

        $this->Agent = strtolower($_SERVER['HTTP_USER_AGENT']);
        foreach($browsers as $browser)
        {
            if (preg_match("#($browser)[/ ]?([0-9.]*)#", $this->Agent, $match))
            {
                $this->Name = $match[1] ;
                $this->Version = $match[2] ;
                break ;
            }
        }
    }

    public function __Get($name)
    {
        if (!array_key_exists($name, $this->props))
        {
            die ("No such property or function $name");
        }
        return $this->props[$name] ;
    }

    public function __Set($name, $val)
    {
        if (!array_key_exists($name, $this->props))
        {
            SimpleError("No such property or function.", "Failed to set $name", $this->props) ;
            die ;
        }
        $this->props[$name] = $val ;
    }

}

$browser = new Browser ;
echo $browser->Name." ". $browser->Version."<br>" ;
if($browser->Name == 'firefox' && $browser->Version <= 3.6){
  echo "Din browser er gammel.";
}
?>